PreprintPDF Available

Appraisal of Experimental Methods to Manage Menopause and Infertility: Intraovarian Platelet-Rich Plasma vs. Condensed Platelet-Derived Cytokines

Authors:
  • FertiGen +CAG
  • Gen 5 Fertility Center

Abstract

The first published description of intraovarian platelet-rich plasma (PRP) appeared in mid-2016, when a new experimental technique was successfully used in adult human ovaries to correct the reduced fertility potential accompanying advanced maternal age. Considering the potential therapeutic scope of intraovarian activated PRP and/or condensed platelet cytokines would likely cover both menopause treatment and infertility, the mainstream response has ranged from skeptical disbelief to welcome astonishment. Indeed, reports of restored menses in menopause (as an alternative to conventional hormone replacement therapy) and healthy term livebirths for infertility patients (either with IVF or as unassisted conceptions) after intraovarian PRP injection continue to draw notice. Yet any proper criticism of ovarian PRP applications will be difficult to rebut given the heterogenous patient screening, varied sample preparations, wide differences in platelet incubation and activation protocols, surgical/anesthesia techniques, and delivery methods. Notwithstanding these features, no adverse events have been reported thus far and ovarian PRP appears well tolerated by patients. Here, early research guiding the transition of ‘ovarian rejuvenation’ from experimental to clinical is outlined. Likely mechanisms are presented to explain results observed in both veterinary and human ovarian PRP research. Current and future challenges for intraovarian cytokine treatment are also discussed.
Medicina
Medicina (Kaunas) 2021;57:xxxxx www.mdpi.com/journal/medicina
Special Communication
1
Appraisal of experimental menopause and infertility treatments:
2
Intraovarian autologous platelet-rich plasma vs. condensed
3
platelet-derived cytokines
4
E. Scott Sills 1,2 *, Samuel H. Wood2,3
5
1Regenerative Biology Group, FertiGen / CAG; San Clemente, California 92673 USA
6
2Department of Obstetrics & Gynecology, Palomar Medical Center; Escondido, California 92029 USA
7
3Gen 5 Fertility Center; San Diego, California 92121 USA
8
9
*Plasma Research Section, FertiGen/CAG, P.O. Box 73910; San Clemente, California 92673 USA
10
email: ess@prp.md Tel: +1 949-899-5686
11
12
Abstract: The first published description of intraovarian platelet-rich plasma (PRP) appeared in mid-2016, when
13
a new experimental technique was successfully used in adult human ovaries to correct the reduced fertility po-
14
tential accompanying advanced maternal age. Considering the potential therapeutic scope of intraovarian acti-
15
vated PRP and/or condensed platelet cytokines would likely cover both menopause treatment and infertility, the
16
mainstream response has ranged from skeptical disbelief to welcome astonishment. Indeed, reports of restored
17
menses in menopause (as an alternative to conventional hormone replacement therapy) and healthy term live-
18
births for infertility patients (either with IVF or as unassisted conceptions) after intraovarian PRP injection con-
19
tinue to draw notice. Yet any proper criticism of ovarian PRP applications will be difficult to rebut given the
20
heterogenous patient screening, varied sample preparations, wide differences in platelet incubation and activa-
21
tion protocols, surgical/anesthesia techniques, and delivery methods. Notwithstanding these features, no adverse
22
events have been reported thus far and ovarian PRP appears well tolerated by patients. Here, early research guid-
23
ing the transition of ‘ovarian rejuvenation’ from experimental to clinical is outlined. Likely mechanisms are pre-
24
sented to explain results observed in both veterinary and human ovarian PRP research. Current and future chal-
25
lenges for intraovarian cytokine treatment are also discussed.
26
Keywords: platelets; cytokines; angiogenesis; embryo; menopause; fertility
27
28
1. Introduction
29
Platelet-rich plasma (PRP) represents a physiologic signaling aggregate comprising
30
hundreds of platelet derived cytokines obtained from blood samples, collected by stand-
31
ard venipuncture [1]. As a refinement of conventional PRP, growth factors of platelet
32
origin may be further processed to enrich this releasate after activation [2]. Interest in PRP
33
applications has grown over the past 15 years, and since 2016 it has attracted particular
34
attention in experimental reproductive biology. Understandably, the claim to ‘rewind the
35
biological clock’ [3] has been cautiously received. It is not known how many IVF clinics
36
now offer ‘ovarian rejuvenation’ although it is a safe assumption the number was zero
37
prior to 2016. In contrast, considerable experience with autologous PRP (fresh and frozen)
38
has already been reported in cardiothoracic surgery [4], scalp hair regrowth [5], derma-
39
tology [6], oral surgery [7], sports medicine [8] and other clinical fields [9]. While the ab-
40
sence of randomized placebo-controlled clinical trials regarding intraovarian PRP must
41
be acknowledged, this deficiency did not block IVF from entering mainstream fertility
42
practice with no RCT support [10].
43
Rejuvenation arrived on the gynecology stage with its (non-pharmacologic) promise
44
to improve ovarian function [11]. Autologous PRP has also been used occasionally as an
45
intrauterine lavage, aiming to boost endometrial receptivity and enhance embryo implan-
46
tation [12]. In the follicular recruitment IVF space, intraovarian PRP joins a crowded cast
47
of untested interventions such as human growth hormone, aspirin, heparin, DHEA,
48
Citation: Sills & Wood
Medicina (Kaunas) 2021;57:xx.
https://doi.org/10.3390/xxx
Academic Editor: xxx
Received: xxx
Accepted: xxx
Published: xxx
Publisher’s Note: MDPI is neutral
regarding jurisdictional claims in
published maps & affiliations.
Copyright ©2021 by the authors.
Submitted for possible open access
publication under terms & conditions
of Creative Commons license
https://creativecommons.org/licenses/by/4.0/
Medicina (Kaunas) 2021;57: FOR PEER REVIEW 2 of 9
antioxidants, and screening hysteroscopy [13]. But what is the basis of the proposed PRP
49
pathway to ovarian rejuvenation?
50
2. Therapeutic Rationale
51
Platelets contain multiple granules which, upon activation, deliver numerous cargo
52
proteins including platelet-derived growth factor (PDGF), fibroblast growth factor (FGF),
53
vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), transforming
54
growth factor-beta 1 (TGF-β1), insulin-like growth factor (IGF), connecting tissue growth
55
factor (CTGF), hepatocyte growth factor (HGF), and others [9,11]. The roster of releasate
56
contents seems ever growing; these moieties orchestrate cellular growth and directs repair
57
following tissue injury. For older or impaired ovarian tissue, small series and case report
58
data suggest this signaling milieu can contribute to improved stromal perfusion, enable
59
an enlarged follicle pool, recruit latent oocytes, and produce healthy term livebirths
60
[14,15].
61
While intraovarian PRP is usually regarded as a precursor to IVF, the ‘reset’ estab-
62
lished after platelet cytokine treatment may confer benefits even if not followed by such
63
complex treatments [15-17]. This could occur due to temporary resolution of tissue dys-
64
function associated with hypoperfusion characteristic of the senescent ovary [11].
65
3. Ovarian PRP: Veterinary and human research
66
What might PRP accomplish in the setting of impaired or even obliterated reserve as
67
with menopause? This question was explored in an animal model where intraperitoneal
68
4-vinylcyclohexene dioxide administration was used as a gonadotoxin for total ovarian
69
collapse. Next, rat intraovarian PRP injections were followed by documentation of cellular
70
changes as well as expression of angiogenic-related transcripts ANGPT2 and KDR via
71
real-time qPCR. While histopathological review confirmed an ovarian insufficiency (POI)
72
state after initial conditions, injection of PRP substantially reduced the extent of follicular
73
atresia and inflammatory response [18]. An uptick was also measured in ANGPT2 and
74
KDR transcript expression in POI rats secondary to enhanced inflammation but reduced
75
after PRP administration vs. controls. Perhaps most crucially, improvement in litter
76
counts was documented among animals receiving PRP compared to the non-treated POI
77
group [18]. This study also found intraovarian PRP also protected morphologically nor-
78
mal follicles from degeneration. This parallels earlier observations among rats with exper-
79
imentally induced PCOS, where improved ovarian antioxidant potential and enhanced
80
follicular development after PRP mitigated deleterious oocyte effects in PCOS [19].
81
Research from Milan [20] described bovine response to administration of autologous
82
intraovarian PRP before programmed superovulation. A significant improvement was
83
noted in mean follicle number between control vs. PRP injected ovaries, and significantly
84
more high-grade blastocysts were generated following PRP use [20]. Additional animal
85
experiments have found a beneficial (rescue) effect of PRP on ovarian function in female
86
rats with ovarian damage induced by cyclophosphamide, concluding this approach could
87
lead to improved primordial, primary, secondary, and antral follicle counts [21].
88
Medicina (Kaunas) 2021;57: FOR PEER REVIEW 3 of 9
89
Figure 1. At least two methods of PRP sample preparation are currently in use, including conven-
90
tional activation (A) and condensed cytokines isolated after in vitro platelet (PLT) incubation/pro-
91
cessing (B). Note that depleted platelets (DEP) are removed (in B) following concentration of platelet
92
releasate. Although bioactivity for both is a function of multiple signaling moieties, the concentra-
93
tion of such growth factors should be markedly increased along path B. Relevant platelet-derived
94
cytokines include Vascular endothelial growth factor (VEGF), a signal protein promoting angiogen-
95
esis; Ligand of CD40 (CD-40L), an inflammatory signal for endothelium, platelets, and leukocytes;
96
Interleukin-1β (IL-1β), an inflammatory marker involved in cell growth, differentiation; Interleukin-
97
8 (IL-8) which initiates angiogenesis, perfusion, and movement to injury/infection sites; PLT derived
98
growth factor (PDGF), essential for vascular development, proliferation of fibroblasts, osteoblasts,
99
tenocytes, vascular SMCs and mesenchymal stem cells; and PLT factor 4 (PF4), central in organizing
100
platelet aggregation.
101
4. Patient & protocol differences
102
Both platelet concentration and derivative cytokine releasate show considerable in-
103
dividual variation [22], and this aspect of PRP treatment is important to review with po-
104
tential patients before ovarian rejuvenation is attempted. At least two techniques exist to
105
process PRP (see Figure 1), although ‘best practice guidelines’ are not yet available to help
106
screen patients or suggest a specific therapy. While a minimum platelet level necessary to
107
elicit a regenerative response probably depends on the intended target tissue, animal re-
108
search [23] found a threshold approaching 1M platelets/mL (i.e., a 3-8 fold enrichment
109
over baseline) as sufficient for bone healing. Of note, these experts did acknowledge a
110
‘more is not always better’ paradigm [23] to highlight the need for additional research.
111
Prospective intraovarian PRP human data (n=182) identified significant differences
112
in baseline platelet count among responders vs. non-responders [24], validating a relation
113
between platelet count and subsequent ovarian reserve post-treatment. Even for women
114
with platelet levels on the lower margin of normal, it might be possible to collect two
115
samples within a few hours to pool autologous blood for aggregate processing and same
116
day (fresh) injection. By facilitating ovarian PRP treatment with an augmented platelet
117
concentration, this may overcome marginally low platelet counts which would otherwise
118
be disqualifying. For cases with absolute thrombocytopenia (PLT <100K), formal hema-
119
tology consult is appropriate as these patients would be high risk for IVF and pregnancy.
120
The impact of handling technique on platelet lysate has also been studied [25], find-
121
ing method of sample preparation can significantly influence the growth factor profile.
122
Specifically, platelet-derived cytokine levels were markedly increased in non-calcium
123
Medicina (Kaunas) 2021;57: FOR PEER REVIEW 4 of 9
activated PRP with a freeze-thaw-freeze incubation; a major disadvantage was also re-
124
ported if room temperature incubation was used [25].
125
Lower PRP concentrations might still block nasoseptal cells from losing their chon-
126
drogenic potential due to in vitro expansion, thereby promoting recommitment [26]. Re-
127
duced concentration of platelet releasate was able to augment mesenchymal stromal cells
128
as noted by upregulated gene expression, sulfated glycosaminoglycan production, and
129
compressive modulus after in vitro culture. Some markers of regenerative action were
130
again impaired at higher concentration of platelet releasate (10%), emphasizing the need
131
to define an optimal sample preparation method [26].
132
Platelet-derived cytokines have been quantified following activation either with cal-
133
cium alone or calcium/thrombin [27]. High concentrations of platelet-derived growth fac-
134
tor, endothelial growth factor, and transforming growth factor (TGF) were secreted with
135
interleukin (IL)-4, IL-8, IL-13, IL-17, tumor necrosis factor (TNF)-α and interferon (IFN)-
136
α. Unsurprisingly, no cytokines were secreted without platelet activation. TGF-β3 and
137
IFNγ were absent in all studied fractions. Clots obtained after platelet coagulation re-
138
tained a high cytokine concentration, including platelet-derived growth factor and TGF
139
[27].
140
Research from colleagues in Ukraine reported on 38 women with low ovarian reserve
141
and at least two failed IVF cycles (age 31-45 yrs) who underwent ovarian PRP [28]. In their
142
experience, route of PRP administration was either via laparoscopy or transvaginal ultra-
143
sound and patients were monitored over one year. Significant improvement in ovarian
144
function was noted after treatment, including 10 pregnancies and delivery of six healthy
145
babies [28]. The largest single-center experience with intraovarian PRP probably remains
146
at Genesis Athens (Greece) [1] where this team actively publishes results on specific pa-
147
tient groups. For example, among menopausal women receiving ovarian PRP, 24 of 30
148
attained restored menstruation and improved hormonal levels/ovarian antral follicle
149
count sometimes as soon as one month after injection [1]. This finding extends results
150
from an earlier questionnaire study (n=80) on quality of life/non-reproductive outcomes
151
where ovarian PRP was administered as an alternative to standard HRT [29]. Due to loss
152
of follow-up after ‘menopause reversal’, no longitudinal data were available on this group
153
to determine duration of treatment effects. Also in 2019, ovarian PRP data were published
154
from a prospective matched cohort study where selected reproductive outcomes were
155
tracked in 20 IVF patients receiving this treatment vs. 20 control IVF patients without
156
ovarian PRP. In this pilot trial, a trend towards improved embryo implantation and live-
157
birth rate was measured among IVF patients who received ovarian PRP [30]. One tech-
158
nique (Segova) mentioned by experts in Serbia reports on a PRP processing method using
159
‘special systems and machines’ to increase growth factor levels up to 18 times the initial
160
concentration [31].
161
5. Considerations & contraindications
162
Before enrolling patients for ovarian PRP or intraovarian injection of condensed
163
plasma cytokines, the same baseline considerations for IVF or HRT should apply. Ovarian
164
PRP patient entry criteria followed during the NIH Clinical Trial [NCT03178695] included
165
patients with at least one ovary, infertility of >1yr duration, at least one prior failed (or
166
canceled) IVF cycle, or amenorrhea for at least three months. However, patients who are
167
otherwise healthy but have undetectable reserve (serum AMH <0.03ng/mL) and consid-
168
ered so unsuited for fertility treatment that they were never allowed to try IVF with native
169
oocytes elsewhere, should not be excluded [32]. At exam, it is important to confirm safe
170
ovarian access via transvaginal ultrasound prior to ovarian PRP. For those where back-
171
ground medical conditions are uncertain, medical clearance is required. Patients with on-
172
going pregnancy, current or previous IgA deficiency, ovarian insufficiency secondary to
173
sex chromosome etiology, prior major lower abdominal surgery resulting in pelvic adhe-
174
sions, anticoagulant use for which plasma infusion is contraindicated, psychiatric disor-
175
der precluding study participation (including active substance abuse or dependence),
176
Medicina (Kaunas) 2021;57: FOR PEER REVIEW 5 of 9
obesity, current smokers, ongoing malignancy, or chronic pelvic pain should be excluded
177
[24].
178
During pre-treatment screening it is important to query aspirin/NSAID use, as agents
179
in this class will attenuate platelet function. Specifically, irreversible inhibition of platelet
180
COX-1 by aspirin suppresses precursors required for downstream cytokine signaling [33].
181
Recent research has clarified the mechanisms involved in aspirin’s brake effect on platelet
182
activation [34] and since platelet activation is essential for ovarian PRP to achieve any
183
therapeutic gain, requiring a NSAID-free window of at least 10d before planned intraovar-
184
ian injection seems reasonable. Likewise, for patients taking pentoxifylline, this medica-
185
tion also merits caution in advance of ovarian PRP as it impairs transforming growth fac-
186
tor-beta and platelet-derived growth factor production [35]. Pentoxifylline also can block
187
platelet-associated cytokine release in some settings [36] and should be avoided to opti-
188
mize overall platelet functional potential.
189
Pre-intake considerations notwithstanding, a published opinion accurately identified
190
weaknesses in ovarian PRP reports currently available [37]. Particularly noted were the
191
paucity of delivery data after ovarian PRP, the heterogeneity of commercial systems used
192
in plasma processing, and absence of pre- vs. post-PRP antral follicle count [37]. Regard-
193
ing the first critique, the nascent phase of autologous plasma factor research explains why
194
delivery data remain confined to small series and case reports. Highlighting the underde-
195
veloped state of ovarian PRP is proper and the call for delivery rate information is a nec-
196
essary message. This is a familiar deficiency, and warrants acceptance against a larger
197
unresolved debate about how best to report ‘success’ for IVF in general [38,39]. The second
198
point on differences in PRP sample handling, processing, and administration is also com-
199
pelling, and represents a serious hurdle to be cleared if usable comparisons are to be de-
200
livered. Few published PRP protocols use the exact same kit for specimen collection and
201
processing, centrifugation ‘spin’ parameters, or which reagent is used for platelet activa-
202
tion. Such differences can impact substrate platelet concentration, its cytokine profile, and
203
efficiency of growth factor release. Normal temporal and biological factors can influence
204
platelet availability make assessments across multiple PRP platforms difficult to compare
205
[9,40]. This variation with ovarian PRP methods presents problems for meaningful cross-
206
center comparisons, yet with description of sample preparation, surgical approach, and
207
full reporting of findings it could actually accelerate better understanding of which PRP
208
technique works best for patients. Concerning antral follicle count data to score response
209
to intraovarian PRP, collecting this information would probably add little to ovarian reju-
210
venation given its limited reproducibility and low measurement consistency secondary to
211
operator and/or ultrasound equipment variation. Serum AMH, in contrast, is much easier
212
to standardize and thus represents a preferred marker for follicular potential/ovarian
213
function [41].
214
Reliable measurement of selected constituent molecular signals derived from plate-
215
lets as a function of activation reagent and in vitro incubation method can offer descriptive
216
information for reproductive biology. Because multiple ways exist to perform ‘ovarian
217
rejuvenation’, it will be useful to document differences in cytokine concentrations by tech-
218
nique. Case report and small series reports, while interesting, are most beneficial for the
219
possible rather than the probable. It has been acknowledged that many IVF techniques
220
now accepted as routine clinical practice once were experimental with humble or obscure
221
origins. As noted here, the safety and efficacy of such treatments should be supported by
222
data ideally from multiple randomized clinical trials [42]. We agree with Kamath et al [13]
223
as caution is appropriate where use of early, investigational techniques are proposed.
224
6. Conclusions
225
The central question of whether or not the adult human ovary retains the capacity to
226
produce de novo oocytes remains open. In postnatal CNS tissues also once thought irre-
227
placeable, a similar issue is found regarding functional recovery and cellular regeneration
228
[43,44]. So under certain conditions, the key objective of cellular regeneration here like-
229
wise may need reconsideration. Working with a murine eye model, upregulation of
230
Medicina (Kaunas) 2021;57: FOR PEER REVIEW 6 of 9
specific genes has restored a ‘youthfulDNA methylation pattern as well as axonal re-
231
growth following tissue damagean approach enabling vision to return after blindness
232
injury in mice [45]. Relevant genes implicated in this transcriptome expression include
233
Sox2, Oct4, and Klf4 [45]. Of note, human platelet lysate has been shown to promote
234
mRNA expression of such ‘mitotic bookmarking factors’ [46]. Building on such studies,
235
reproductive biology can gain much to determine if these (or other) signals are operant in
236
postnatal ovarian function. Small series and case data now exist to describe reproductive
237
outcomes after intraovarian PRP or platelet-derived cytokines. While experience with se-
238
rum AMH (as an estimate of ovarian reserve) following autologous ovarian PRP requires
239
multicenter validation, additional research to characterize specific PRP cytokine compo-
240
nents will be even more useful.
241
Observations discussed here from clinical work in ovarian rejuvenation favor a hy-
242
pothesis for derivative neovascularity to modulate oocyte competence, by augmenting
243
cellular oxygenation and/or reducing levels of intraovarian reactive oxygen species [11].
244
Of note, subsequent experimental animal research found ovarian function and follicular
245
development were indeed promoted after VEGF-mediated vascular remodeling [47].
246
The need for rigorous RCT data on intraovarian insertion of platelet-derived cyto-
247
kines before this innovation enters accepted IVF practice should be viewed as familiar
248
terrain for reproductive medicine [10,48]. Declining ovarian reserve and ineffective fertil-
249
ity responses have become more formidable with advanced maternal age and cannot be
250
defeated by gonadotropins alone. Similarly, perimenopause marks a symptomatic decay
251
in female sex hormone output which at present is usually managed by exogenous hor-
252
mone replacement therapy [49,50]. For both patient populations, the prospect of effective
253
‘ovarian rejuvenation’ would hold considerable appeal. Could autologous platelet cyto-
254
kines help meet this need? While a postnatal folliculogenesis model might explain im-
255
proved ovarian function among older women, important challenges remain [51,52]. A
256
population of adult ovarian germline stem cells might be latentbut availablefor dif-
257
ferentiation, the exact process through which cytokines induce such development requires
258
additional study. What has been suggested from early reports on platelet cytokines sug-
259
gests these moieties can initiate morphogenetic processes normally seen during evolution-
260
ary development [53]. Of note, recent observations in two species of sacoglossan snail
261
(gastropoda) have demonstrated extreme regeneration wherein a severed head was able
262
to regrow an entire new body within approximately 20 days [54]. Unless a parallel process
263
can be discovered to achieve limited postnatal replenishment of the human oocyte pool,
264
reliance on IVF with donor oocytes will continue. Meanwhile, characterization of the ac-
265
tivated PRP substrate, its derivative growth factor profile, receptor targets, optimal sam-
266
ple delivery, and ideally RCT data to support this treatment are still needed.
267
Authors’ Contributions
268
Both authors contributed equally to the work and approved the final version of the
269
manuscript.
270
Acknowledgment
271
Ann-Marie C. Sills (Fundación Santiago Apóstol, Villanueva de la Cañada; Madrid SPAIN)
272
is thanked for editorial assistance with this manuscript.
273
Declaration of Conflicting Interests
274
The authors have been awarded a provisional U.S. Patent for process and treatment using
275
autologous platelet-derived cytokines for ovarian therapy.
276
Funding
277
Medicina (Kaunas) 2021;57: FOR PEER REVIEW 7 of 9
This research received no specific grant from any funding agency in public, commercial,
278
or not-for-profit sectors.
279
References
280
281
1. Sfakianoudis K, Simopoulou M, Grigoriadis S, Pantou A, Tsioulou P, Maziotis E et al. Reactivating ovarian function
282
through autologous platelet-rich plasma intraovarian infusion: Pilot data on premature ovarian insufficiency, perimeno-
283
pausal, menopausal, and poor responder women. J Clin Med 2020;9:1809. DOI: http://dx.doi.org/10.3390/jcm9061809
284
2. Sills ES, Rickers NS, Svid CS, Rickers JM, Wood SH. Normalized ploidy following 20 consecutive blastocysts with chromo-
285
somal error: Healthy 46,XY pregnancy with IVF after intraovarian injection of autologous enriched platelet-derived growth
286
factors. Int J Mol Cell Med 2019;8:84-90. DOI: http://dx.doi.org/10.22088/IJMCM.BUMS.8.1.84
287
3. Pantos K, Nitsos N, Kokkali G, Vaxevanoglou T, Markomichali C, Pantou A et al. Ovarian rejuvenation and folliculogenesis
288
reactivation in peri-menopausal women after autologous platelet rich plasma treatment [abstract]. ESHRE 32nd annual
289
meeting; 2016 Jul 3-6; Helsinki, Finland. Hum Reprod 2016;Suppl 1:i301. DOI: https://sa1s3.patientpop.com/as-
290
sets/docs/111052.pdf
291
4. Yao D, Feng G, Zhao F, Hao D. Effects of platelet-rich plasma on the healing of sternal wounds: A meta-analysis. Wound
292
Repair Regen 2020 Oct 31. DOI: http://dx.doi.org/10.1111/wrr.12874
293
5. Dervishi G, Liu H, Peternel S, Labeit A, Peinemann F. Autologous platelet-rich plasma therapy for pattern hair loss: A
294
systematic review. J Cosmet Dermatol 2020;19:827-35. DOI: http://dx.doi.org/10.1111/jocd.13113
295
6. Dunn A, Long T, Kleinfelder RE, Zarraga MB. The adjunct use of platelet-rich plasma in split-thickness skin grafts: A sys-
296
tematic review. Adv Skin Wound Care 2020 Dec 4. DOI: http://dx.doi.org/10.1097/01.ASW.0000722764
297
7. Sethi Ahuja U, Puri N, More CB, Gupta R, Gupta D. Comparative evaluation of effectiveness of autologous platelet rich
298
plasma and intralesional corticosteroids in the management of erosive oral Lichen planus- a clinical study. J Oral Biol Cra-
299
niofac Res 2020;10:714-8. DOI: http://dx.doi/org/10.1016/j.jobcr.2020.09.008
300
8. Everts P, Onishi K, Jayaram P, Lana JF, Mautner K. Platelet-rich plasma: New performance understandings and therapeutic
301
considerations in 2020. Int J Mol Sci 2020;21:7794. DOI: http://dx.doi.org/10.3390/ijms21207794
302
9. Gentile P, Garcovich S. Systematic review-The potential implications of different platelet-rich plasma (PRP) concentrations
303
in regenerative medicine for tissue repair. Int J Mol Sci 2020;21:5702. DOI: http://dx.doi.org/10.3390/ijms21165702
304
10. Evers JLHH. Do we need an RCT for everything? Hum Reprod 2017;32(3):483-484. DOI: http://dx.doi.org/10.1093/hum-
305
rep/dex003
306
11. Wood SH, Sills ES. Intraovarian vascular enhancement via stromal injection of platelet-derived growth factors: Exploring
307
subsequent oocyte chromosomal status and in vitro fertilization outcomes. Clin Exp Reprod Med 2020;47:94-100. DOI:
308
http://dx.doi.org/10.5653/cerm.2019.03405
309
12. Bos-Mikich A, Ferreira MO, de Oliveira R, Frantz N. Platelet-rich plasma or blood-derived products to improve endome-
310
trial receptivity? J Assist Reprod Genet 2019;36:613-20. DOI: http://dx.doi.org/10.1007/s10815-018-1386-z
311
13. Kamath MS, Mascarenhas M, Franik S, Liu E, Sunkara SK. Clinical adjuncts in in vitro fertilization: a growing list. Fertil
312
Steril 2019;112:978-86. DOI: http://dx.doi.org/10.1016/j.fertnstert.2019.09.019
313
14. Sfakianoudis K, Simopoulou M, Nitsos N, Rapani A, Pantou A, Vaxevanoglou T et al. A case series on platelet-rich plasma
314
revolutionary management of poor responder patients. Gynecol Obstet Invest 2019;84:99-106. DOI:
315
http://dx.doi.org/10.1159/000491697
316
15. Farimani M, Heshmati S, Poorolajal J, Bahmanzadeh M. A report on three live births in women with poor ovarian response
317
following intra-ovarian injection of platelet-rich plasma (PRP). Mol Biol Rep 2019;46:1611-6. DOI:
318
http://dx.doi.org/10.1007/s11033-019-04609-w
319
16. Sills ES, Rickers NS, Wood SH. Intraovarian insertion of autologous platelet growth factors as cell-free concentrate: Fertility
320
recovery and first unassisted conception with term delivery at age over 40. Int J Reprod Biomed 2020;18:1081-6. DOI:
321
http://dx.doi.org/10.18502/ijrm.v18i12.8030
322
17. Sfakianoudis K, Rapani A, Grigoriadis S, Retsina D, Maziotis E, Tsioulou P et al. Novel approaches in addressing ovarian
323
insufficiency in 2019: Are we there yet? Cell Transplant 2020;29:963689720926154. DOI:
324
http://dx.doi.org/10.1177/0963689720926154
325
18. Ahmadian S, Sheshpari S, Pazhang M, Bedate AM, Beheshti R, Abbasi MM et al. Intra-ovarian injection of platelet-rich
326
plasma into ovarian tissue promoted rejuvenation in the rat model of premature ovarian insufficiency and restored ovula-
327
tion rate via angiogenesis modulation. Reprod Biol Endocrinol 2020;18:78. DOI: http://dx.doi.org/10.1186/s12958-020-00638-4
328
19. Anvari SS, Dehgan GH, Razi M. Preliminary findings of platelet-rich plasma induced ameliorative effect on polycystic
329
ovarian syndrome. Cell J 2019;21:243-52. DOI: http://dx.doi.org/10.22074/cellj.2019.5952
330
20. Cremonesi F, Bonfanti S, Idda A, Anna LC. Improvement of embryo recovery in Holstein cows treated by intraovarian
331
platelet rich plasma before superovulation. Vet Sci 2020;7:16. DOI: http://dx.doi.org/10.3390/vetsci7010016
332
21. Ozcan P, Takmaz T, Tok OE, Islek S, Yigit EN, Ficicioglu C. The protective effect of platelet-rich plasma administrated on
333
ovarian function in female rats with Cy-induced ovarian damage. J Assist Reprod Genet 2020;37:865-73. DOI:
334
http://dx.doi.org/10.1007/s10815-020-01689-7
335
22. Sundman EA, Cole BJ, Fortier LA. Growth factor and catabolic cytokine concentrations are influenced by the cellular com-
336
position of platelet-rich plasma. Am J Sports Med 2011;39:213540. DOI: http://dx.doi.org/10.1177/0363546511417792
337
Medicina (Kaunas) 2021;57: FOR PEER REVIEW 8 of 9
23. Weibrich G, Hansen T, Kleis W, Buch R, Hitzler WE. Effect of platelet concentration in platelet-rich plasma on peri-implant
338
bone regeneration. Bone 2004;34:66571. DOI: http://dx.doi.org/10.1016/j.bone.2003.12.010
339
24. Sills ES, Rickers NS, Petersen JL, Li X, Wood SH. Regenerative effect of intraovarian injection of activated autologous plate-
340
let-rich plasma: Serum anti-Mullerian hormone levels measured among poor-prognosis in vitro fertilization patients
341
[NCT03178695]. Int J Regenerative Med 2020;3:1-5. DOI: https://dx.doi.org/10.31487/j.RGM.2020.01.02
342
25. Steller D, Herbst N, Pries R, Juhl D, Hakim SG. Impact of incubation method on the release of growth factors in non-Ca2+-
343
activated PRP, Ca2+-activated PRP, PRF and A-PRF. J Craniomaxillofac Surg 2019;47:365-72. DOI:
344
http://dx.doi.org/10.1016/j.jcms.2018.10.017
345
26. do Amaral RJ, Matsiko A, Tomazette MR, Rocha WK, Cordeiro-Spinetti E, Levingstone TJ et al. Platelet-rich plasma re-
346
leasate differently stimulates cellular commitment toward the chondrogenic lineage according to concentration. J Tissue
347
Eng 2015;6:2041731415594127. DOI: http://dx.doi.org/10.1177/2041731415594127
348
27. Machado ES, Leite R, Dos Santos CC, Artuso GL, Gluszczak F, de Jesus LG et al. Turn down - turn up: a simple and low-
349
cost protocol for preparing platelet-rich plasma. Clinics (Sao Paulo) 2019;74:e1132. DOI: http://dx.doi.org/10.6061/clin-
350
ics/2019/e1132
351
28. Amable PR, Carias RB, Teixeira MV, da Cruz Pacheco I, Corrêa do Amaral RJ, Granjeiro JM et al. Platelet-rich plasma
352
preparation for regenerative medicine: optimization and quantification of cytokines and growth factors. Stem Cell Res Ther
353
2013;4:67. DOI: http://dx.doi.org/10.1186/scrt218
354
29. Petryk N, Petryk M. Ovarian rejuvenation through platelet-rich autologous plasma (PRP)-a chance to have a baby without
355
donor eggs, improving the life quality of women suffering from early menopause without synthetic hormonal treatment.
356
Reprod Sci 2020;27:1975-82. DOI: http://dx.doi.org/10.1007/s43032-020-00266-8
357
30. Sills ES, Li X, Rickers NS, Wood SH, Palermo GD. Metabolic and neurobehavioral response following intraovarian admin-
358
istration of autologous activated platelet rich plasma: First qualitative data. Neuroendocrinol Lett 2019;39:427-33. PMID:
359
30796792.
360
31. Stojkovska S, Dimitrov G, Stamenkovska N, Hadzi-Lega M, Petanovski Z. Livebirth rates in poor responders' group after
361
previous treatment with autologous platelet-rich plasma and low dose ovarian stimulation compared with poor responders
362
used only low dose ovarian stimulation before in vitro fertilization. Open Access Maced J Med Sci 2019;7:3184-8. DOI:
363
http://dx.doi.org/10.3889/oamjms.2019.825
364
32. Tinjic S, Abazovic D, Ljubic D, Vujovic S, Vojvodic D, Božanovic T et al. Ovarian rejuvenation. Donald Sch J Ultrasound
365
Obstet Gynecol 2019;13:64-8. DOI: http://dx.doi.org/10.5005/jp-journals-10009-1587
366
33. U.S. National Library of Medicine. Autologous platelet-rich plasma (PRP) infusions and biomarkers of ovarian rejuvenation
367
and ageing mitigation [NCT03178695]; March 7, 2017. https://clinicaltrials.gov/ct2/show/NCT03178695
368
34. Schrör K. Aspirin and platelets: the antiplatelet action of aspirin and its role in thrombosis treatment and prophylaxis.
369
Semin Thromb Hemost 1997;23:349-56. DOI: http://dx.doi.org/10.1055/s-2007-996108
370
35. Qi Z, Hu L, Zhang J, Yang W, Liu X, Jia D et al. PCSK9 enhances platelet activation, thrombosis, and myocardial infarct
371
expansion by binding to Platelet CD36. Circulation 2020 Sep 29. DOI: http://dx.doi.org/10.1161/CIRCULA-
372
TIONAHA.120.046290
373
36. Wu J, Zern MA. Hepatic stellate cells: a target for the treatment of liver fibrosis. J Gastroenterol 2000;35(9):665-72. DOI:
374
http://dx.doi.org/10.1007/s005350070045
375
37. Tong Z, Dai H, Chen B, Abdoh Z, Guzman J, Costabel U. Inhibition of cytokine release from alveolar macrophages in
376
pulmonary sarcoidosis by pentoxifylline: comparison with dexamethasone. Chest 2003;124:1526-32. DOI:
377
http://dx.doi.org/10.1378/chest.124.4.1526
378
38. Urman B, Boza A. Reply: Every established treatment had been experimental at the beginning. Hum Reprod 2020;35:1720-1.
379
DOI: http://dx.doi.org/10.1093/humrep/deaa122
380
39. Kushnir VA, Barad DH, Gleicher N. Defining assisted reproductive technology success. Fertil Steril 2013;100:e30. DOI:
381
http://dx.doi.org/10.1016/j.fertnstert.2013.08.036
382
40. Gunderson S, Jungheim ES, Kallen CB, Omurtag K. Public reporting of IVF outcomes influences medical decision-making
383
and physician training. Fertil Res Pract 2020;6:1. DOI: http://dx.doi.org/10.1186/s40738-020-00070-7
384
41. Dhurat R, Sukesh MS. Principles and methods of preparation of platelet-rich plasma: A review and author's perspective. J
385
Cutan Aesthet Surg 2014;7:189-97. DOI: http://dx.doi.org/10.4103/0974-2077.150734
386
42. Liu L, Zhou C. Anti-Mullerian hormone and antral follicle count differ in their ability to predict cumulative treatment
387
outcomes of the first complete ovarian stimulation cycle in patients from POSEIDON groups 3 and 4. J Obstet Gynaecol Res
388
2020;46:1801-8. DOI: http://dx.doi.org/10.1111/jog.14269
389
43. Goldberg JL, Klassen MP, Hua Y, Barres BA. Amacrine-signaled loss of intrinsic axon growth ability by retinal ganglion
390
cells. Science 2002;296:18601864. DOI: http://dx.doi.org/10.1126/science.1068428
391
44. Yun MH. Changes in regenerative capacity through lifespan. Int J Mol Sci 2015;16(10):25392-432. DOI:
392
http://dx.doi.org/10.3390/ijms161025392
393
45. Lu Y, Brommer B, Tian X, Krishnan A, Meer M, Wang C et al. Reprogramming to recover youthful epigenetic information
394
and restore vision. Nature 2020;588(7836):124-129. DOI: http://dx.doi.org/10.1038/s41586-020-2975-4
395
46. Laner-Plamberger S, Oeller M, Mrazek C, Hartl A, Sonderegger A, Rohde E et al. Upregulation of mitotic bookmarking
396
factors during enhanced proliferation of human stromal cells in human platelet lysate. J Transl Med 2019;17(1):432. DOI:
397
http://dx.doi.org/10.1186/s12967-019-02183-0
398
Medicina (Kaunas) 2021;57: FOR PEER REVIEW 9 of 9
47. Cho J, Kim TH, Seok J, Jun JH, Park H, Kweon M et al. Vascular remodeling by placenta-derived mesenchymal stem cells
399
restores ovarian function in ovariectomized rat model via the VEGF pathway. Lab Invest 2021;101:304-317. DOI:
400
http://dx.doi.org/10.1038/s41374-020-00513-1
401
48. Harper J, Jackson E, Sermon K, Aitken RJ, Harbottle S, Mocanu E et al. Adjuncts in the IVF laboratory: where is the evidence
402
for 'add-on' interventions? Hum Reprod 2017;32(3):485-491. DOI: http://dx.doi.org/10.1093/humrep/dex004
403
49. Urman B, Boza A, Balaban B. Platelet-rich plasma another add-on treatment getting out of hand? How can clinicians pre-
404
serve the best interest of their patients? Hum Reprod 2019;34:2099-103. DOI: http://dx.doi.org/10.1093/humrep/dez190
405
50. Sills ES. The scientific and cultural journey to ovarian rejuvenation: Background, barriers, and beyond the biological clock.
406
Medicines (Basel) 2021;8(6):29. DOI: http://dx.doi.org/10.3390/medicines8060029
407
51. Hanna CB, Hennebold JD. Ovarian germline stem cells: an unlimited source of oocytes? Fertil Steril 2014;101;20-30. DOI:
408
http://dx.doi.org/10.1016/j.fertnstert.2013.11.009
409
52. Dunlop CE, Telfer EE, Anderson RA. Ovarian stem cellspotential roles in infertility treatment and fertility preservation.
410
Maturitas 2013;76:279-83. DOI: http://dx.doi.org/10.1016/j.maturitas.2013.04.017
411
53. Yuan J, Zhang D, Wang L, Liu M, Mao J, Yin Y et al. No evidence for neo-oogenesis may link to ovarian senescence in adult
412
monkey. Stem Cells 2013;31:2538-50. DOI: http://dx.doi.org/10.1002/stem.1480
413
54. Mitoh S, Yusa Y. Extreme autotomy and whole-body regeneration in photosynthetic sea slugs. Curr Biol 2021;31:R233-R234.
414
DOI: http://dx.doi.org/10.1016/j.cub.2021.01.014
415
ResearchGate has not been able to resolve any citations for this publication.
Article
Full-text available
Female age has been known to define reproductive outcome since antiquity; attempts to improve ovarian function may be considered against a sociocultural landscape that foreshadows current practice. Ancient writs heralded the unlikely event of an older woman conceiving as nothing less than miraculous. Always deeply personal and sometimes dynastically pivotal, the goal of achieving pregnancy often engaged elite healers or revered clerics for help. The sorrow of defeat became a potent motif of barrenness or miscarriage lamented in art, music, and literature. Less well known is that rejuvenation practices from the 1900s were not confined to gynecology, as older men also eagerly pursued methods to turn back their biological clock. This interest coalesced within the nascent field of endocrinology, then an emerging specialty. The modern era of molecular science is now offering proof-of-concept evidence to address the once intractable problem of low or absent ovarian reserve. Yet, ovarian rejuvenation by platelet-rich plasma (PRP) originates from a heritage shared with both hormone replacement therapy (HRT) and sex reassignment surgery. These therapeutic ancestors later developed into allied, but now distinct, clinical fields. Here, current iterations of intraovarian PRP are discussed with historical and cultural precursors centering on cell and tissue regenerative effects. Intraovarian PRP thus shows promise for women in menopause as an alternative to conventional HRT, and to those seeking pregnancy—either with advanced reproductive technologies or as unassisted conceptions.
Article
Full-text available
Background: The use of autologous platelet-rich plasma as an ovarian treatment has not been standardized and remains controversial. Case Presentation: A 41½-year old woman with diminished ovarian reserve (serum anti- Müllerian hormone = 0.163 mg/mL) and a history of 10 unsuccessful in vitro fertilization cycles presented for reproductive endocrinology consult. She and her partner declined donor oocyte in vitro fertilization. They were both in good general health and laboratory tests were unremarkable, except for mild thrombocytosis (platelets = 386K; normal range 150-379K) discovered in the female. The patient underwent intraovarian injection of fresh platelet-derived growth factor concentrate administered as an enriched cell-free substrate. Serum anti- Müllerian hormone increased by 115% within 6 wks of treatment. Spontaneous ovulation occurred the month after injection and subsequently the serum human chorionic gonadotropin was noted at 804 mIU/mL. Following an uneventful obstetrical course, a male infant was delivered at term without complication. Conclusion: This is the first description of intraovarian injection of enriched platelet-derived growth factors followed by unassisted pregnancy and live birth. As a refinement of conventional ovarian platelet-rich plasma therapy, this procedure may be particularly valuable for refractory cases where prognosis for pregnancy appears especially bleak. A putative role for thrombocytosis is also viewed in parallel with mechanisms of action as advanced earlier. With continued experience in ovarian application of autologous platelet growth factors, additional research will evaluate laboratory protocol/sample preparation, injection technique, and patient selection.
Article
Full-text available
Angiogenesis plays an important role in damaged organ or tissue and cell regeneration and ovarian development and function. Primary ovarian insufficiency (POI) is a prevalent pathology in women under 40. Conventional treatment for POI involves hormone therapy. However, due to its side effects, an alternative approach is desirable. Human mesenchymal stem cells (MSCs) from various sources restore ovarian function; however, they have many limitations as stem cell sources. Therefore, it is desirable to study the efficacy of placenta-derived MSCs (PD-MSCs), which possess many advantages over other MSCs, in a rat model of ovarian dysfunction. Here, we investigated the restorative effect of PD-MSCs on injured ovaries in ovariectomized (OVX) rats and the ability of intravenous transplantation (Tx) of PD-MSCs (5 × 10 ⁵ ) to enhance ovarian vasculature and follicular development. ELISA analysis of serum revealed that compared to the non-transplantation (NTx) group, the Tx group showed significantly increased levels of anti-Müllerian hormone, follicle stimulating hormone, and estradiol (E2) (* P < 0.05). In addition, histological analysis showed more mature follicles and less atresia and restoration of expanded blood vessels in the ovaries of the OVX PD-MSC Tx group than those of the NTx group (* P < 0.05). Furthermore, folliculogenesis-related gene expression was also significantly increased in the PD-MSC Tx group (* P < 0.05). Vascular endothelial growth factor (VEGF) and VEGF receptor 2 expressions were increased in the ovaries of the OVX PD-MSC Tx group compared to the NTx group through PI3K/AKT/mTOR and GSK3β/β-catenin pathway activation. Interestingly, ex vivo cocultivation of damaged ovaries and PD-MSCs or treatment with recombinant VEGF (50 ng/ml) increased folliculogenic factors and VEGF signaling pathways. Notably, compared to recombinant VEGF, PD-MSCs significantly increased folliculogenesis and angiogenesis (* P < 0.05). These findings suggest that VEGF secreted by PD-MSCs promotes follicular development and ovarian function after OVX through vascular remodeling. Therefore, these results provide fundamental data for understanding the therapeutic effects and mechanism of stem cell therapy based on PD-MSCs and provide a theoretical foundation for their application for obstetrical and gynecological diseases, including infertility and menopause.
Article
Full-text available
Ageing is a degenerative process that leads to tissue dysfunction and death. A proposed cause of ageing is the accumulation of epigenetic noise that disrupts gene expression patterns, leading to decreases in tissue function and regenerative capacity1–3. Changes to DNA methylation patterns over time form the basis of ageing clocks⁴, but whether older individuals retain the information needed to restore these patterns—and, if so, whether this could improve tissue function—is not known. Over time, the central nervous system (CNS) loses function and regenerative capacity5–7. Using the eye as a model CNS tissue, here we show that ectopic expression of Oct4 (also known as Pou5f1), Sox2 and Klf4 genes (OSK) in mouse retinal ganglion cells restores youthful DNA methylation patterns and transcriptomes, promotes axon regeneration after injury, and reverses vision loss in a mouse model of glaucoma and in aged mice. The beneficial effects of OSK-induced reprogramming in axon regeneration and vision require the DNA demethylases TET1 and TET2. These data indicate that mammalian tissues retain a record of youthful epigenetic information—encoded in part by DNA methylation—that can be accessed to improve tissue function and promote regeneration in vivo.
Article
Full-text available
Emerging autologous cellular therapies that utilize platelet-rich plasma (PRP) applications have the potential to play adjunctive roles in a variety of regenerative medicine treatment plans. There is a global unmet need for tissue repair strategies to treat musculoskeletal (MSK) and spinal disorders, osteoarthritis (OA), and patients with chronic complex and recalcitrant wounds. PRP therapy is based on the fact that platelet growth factors (PGFs) support the three phases of wound healing and repair cascade (inflammation, proliferation, remodeling). Many different PRP formulations have been evaluated, originating from human, in vitro, and animal studies. However, recommendations from in vitro and animal research often lead to different clinical outcomes because it is difficult to translate non-clinical study outcomes and methodology recommendations to human clinical treatment protocols. In recent years, progress has been made in understanding PRP technology and the concepts for bioformulation, and new research directives and new indications have been suggested. In this review, we will discuss recent developments regarding PRP preparation and composition regarding platelet dosing, leukocyte activities concerning innate and adaptive immunomodulation, serotonin (5-HT) effects, and pain killing. Furthermore, we discuss PRP mechanisms related to inflammation and angiogenesis in tissue repair and regenerative processes. Lastly, we will review the effect of certain drugs on PRP activity, and the combination of PRP and rehabilitation protocols.
Article
Full-text available
Background: Proprotein convertase subtilisin/kexin 9 (PCSK9), mainly secreted by the liver and released into the blood, elevates plasma low-density lipoprotein (LDL) cholesterol by degrading LDL receptor. Pleiotropic effects of PCSK9 beyond lipid-metabolism have been shown. However, the direct effects of PCSK9 on platelet activation and thrombosis, as well as the underlying mechanisms, still remain unclear. Methods: We detected the direct effects of PCSK9 on agonists-induced platelet aggregation, dense granule ATP release, integrin αIIbβ3 activation, α granule release, spreading, and clot retraction. These studies were complemented by in vivo analysis of FeCl3-injured mouse mesenteric arteriole thrombosis. We also investigated the underlying mechanisms. Using myocardial infarct (MI) model, we explored the effects of PCSK9 on microvascular obstruction and infarct expansion post-MI. Results: PCSK9 directly enhances agonists-induced platelet aggregation, dense granule ATP release, integrin αIIbβ3 activation, P-selection release from α granules, spreading, and clot retraction. In line, PCSK9 enhances in vivo thrombosis in a FeCl3-injured mesenteric arteriole thrombosis mouse model, while PCSK9 inhibitor evolocumab ameliorates its enhancing effects. Mechanism studies revealed that PCSK9 binds to platelet CD36 and thus activates Src kinase and mitogen-activated protein kinase (MAPK)- extracellular signal-regulated kinase 5 and c-Jun N-terminal kinase, increases the generation of reactive oxygen species, as well as activates the p38MAPK/cytosolic phospholipase A2/cyclooxygenase-1/thromboxane A 2 signaling pathways downstream of CD36 to enhance platelet activation. Using CD36 knockout mice, we showed the enhancing effects of PCSK9 on platelet activation are CD36 dependent. Consistently and importantly, aspirin abolishes the enhancing effects of PCSK9 on platelet activation and in vivo thrombosis. Finally, we showed that PCSK9 activating platelet CD36 aggravates microvascular obstruction and promotes MI expansion post-MI. Conclusions: PCSK9 in plasma directly enhances platelet activation and in vivo thrombosis, as well as MI expansion post-MI, by binding to platelet CD36 and thus activating the downstream signaling pathways. PCSK9 inhibitors or aspirin abolish the enhancing effects of PCSK9, supporting the use of aspirin in patients with high plasma PCSK9 levels in addition to PCSK9 inhibitors to prevent thrombotic complications.
Article
Full-text available
The number of studies evaluating platelet-rich plasma (PRP) concentration has substantially grown in the last fifteen years. A systematic review on this field has been realized by evaluating in the identified studies the in vitro PRP concentration—also analyzing the platelet amount—and the in vivo PRP effects in tissue regeneration compared to any control. The protocol has been developed in agreement with the Preferred Reporting for Items for Systematic Reviews and Meta-Analyses-Protocols (PRISMA-P) guidelines. Multistep research of the PubMed, MEDLINE, Embase, PreMEDLINE, Ebase, CINAHL, PsycINFO, Clinicaltrials.gov, Scopus database and Cochrane databases has permitted to identify articles on different concentrations of PRP in vitro and related in vivo impact for tissue repair. Of the 965 articles initially identified, 30 articles focusing on PRP concentration have been selected and, consequently, only 15 articles have been analyzed. In total, 40% (n = 6) of the studies were related to the fixed PRP Concentration Group used a fixed PRP concentration and altered the platelet concentration by adding the different volumes of the PRP (lysate) to the culture. This technique led to a substantial decrease in nutrition available at higher concentrations. Sixty percent (n = 9) of the studies were related to the fixed PRP Volume Group that used a fixed PRP-to-media ratio (Vol/Vol) throughout the experiment and altered the concentration within the PRP volume. For both groups, when the volume of medium (nutrition) decreases, a lower rate of cell proliferation is observed. A PRP concentration of 1.0 × 106 plt/μL, appears to be optimal thanks to the constant and plentiful capillary nutrition supply and rapid diffusion of growth factors that happen in vivo and it also respects the blood decree-law. The PRP/media ratio should provide a sufficient nutrition supply to prevent cellular starvation, that is, PRP ≤ 10% (Vol/Vol) and thus best mimic the conditions in vivo.
Article
Full-text available
Abstract Premature Ovarian Insufficiency (POI) is viewed as a type of infertility in which the menopausal status occurs before the physiological age. Several therapeutic strategies have been introduced in clinic for POI treatment, although the outputs are not fully convincing. Platelet-rich plasma (PRP) is a unique blood product widely applied in regenerative medicine, which is based on the releasing of the growth factors present in platelets α-granules. In the current investigation, we examined the effectiveness of PRP as a therapeutic alternative for POI animals. POI in Wistar albino rats was induced by daily intraperitoneal (IP) administration of gonadotoxic chemical agent, 4-vinylcyclohexene dioxide (VCD) (160 mg/ kg) for 15 consecutive days. After POI induction, the PRP solution was directly injected intra-ovarian in two concentrations via a surgical intervention. Every two weeks post-injection, pathological changes were monitored in the ovaries using Hematoxylin-Eosin staining method, until eight weeks. Follicle Stimulating Hormone (FSH) content in serum was measured, together with the expression of the angiogenic-related transcripts ANGPT2 and KDR by real-time qPCR. Furthermore the fertility status of the treated rats was evaluated by mating trials. Histopathological examination revealed successful POI induction via the depletion of morphologically normal follicles in rats following VCD treatment compared to the control rats. The injection of PRP at two concentrations reduced the number and extent of the follicular atresia and inflammatory responses (p
Article
Autotomy, the voluntary shedding of a body part, is common to distantly-related animals such as arthropods, gastropods, asteroids, amphibians, and lizards¹,². Autotomy is generally followed by regeneration of shed terminal body parts, such as appendages or tails. Here, we identify a new type of extreme autotomy in two species of sacoglossan sea slug (Mollusca: Gastropoda). Surprisingly, they shed the main body, including the whole heart, and regenerated a new body. In contrast, the shed body did not regenerate the head. These sacoglossans can incorporate chloroplasts from algal food into their cells to utilise for photosynthesis (kleptoplasty³), and we propose that this unique characteristic may facilitate survival after autotomy and subsequent regeneration.
Article
Sternal wound infection (SWI) is a devastating complication after cardiac surgery. Platelet‐rich plasma (PRP) may have a positive impact on sternal wound healing. A systematic review with meta‐analyses was performed to evaluate the clinical effectiveness of topical application of autologous PRP for preventing SWI and promoting sternal wound healing compared to placebo or standard treatment without PRP. Relevant studies published in English or Chinese were retrieved from the Cochrane Central Register of Controlled Trials (The Cochrane Library), PubMed, Ovid EMBASE, Web of Science, Springer Link, and the WHO International Clinical Trials Registry Platform (ICTRP) using the search terms “platelet‐rich plasma” and “sternal wound” or “thoracic incision.” References identified through the electronic search were screened, the data were extracted, and the methodological quality of the included studies was assessed. The meta‐analysis was performed for the following outcomes: incidence of SWI, incidence of deep sternal wound infection (DSWI), postoperative blood loss (PBL), and other risk factors. In the systematic review, totally 10 comparable studies were identified, involving 7879 patients. The meta‐analysis for the subgroup of retrospective cohort studies (RSCs) showed that the incidence of SWI and DSWI in patients treated with PRP was significantly lower than that in patients without PRP treatment. However, for the subgroup of randomized controlled trials (RCTs), there was no significant difference in the incidence of SWI or DSWI after intervention between the PRP and control groups. There was no significant difference in PBL in both RCTs and RSCs subgroups. Neither adverse reactions nor in‐situ recurrences were reported. According to the results, PRP could be considered as a candidate treatment to prevent SWI and DSWI. However, the quality of the evidence is too weak, and high‐quality RCTs are needed to assess its efficacy on preventing SWI and DSWI.