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Microneedle‐Based Local Delivery of CCL22 and IL‐2 Enriches Treg Homing to the Skin Allograft and Enables Temporal Monitoring of Immunotherapy Efficacy

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Advanced Functional Materials
Authors:
Núria Puigmal at Harvard Medical School
Núria Puigmal
Pere Dosta Pons at Harvard Medical School
Pere Dosta Pons
Zhabiz Solhjou at Brigham and Women's Hospital
Zhabiz Solhjou
Karim Yatim
Karim Yatim
Karim Yatim
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Abstract and Figures

Skin allografts only serve as temporary dressing for patients suffering major burns due to their high immunogenicity and rejection by the immune system, requiring systemic immunosuppressive therapies that lead to deleterious side effects. Microneedle arrays composed of hyaluronic acid (HA) and placed on skin allografts can locally deliver immunomodulators and simultaneously sample immune cells in interstitial fluid to monitor the response to the therapy. The cells can be retrieved from the microneedles for downstream analysis by degrading the HA using a reducing agent. Using an allogeneic skin transplantation model, it is shown that the microneedle‐mediated local delivery of the chemokine CCL22 (to attract Tregs) and the cytokine IL‐2 (to promote their expansion) increases the local immune suppression in the allograft. Moreover, immune cell population in the allograft correlates with that seen in the microneedles. The delivery and sampling functions of the microneedle arrays can help regulate the immune system locally, without inducing systemic immune suppression, and facilitate the monitoring of the response to the therapy following skin transplantation. Microneedle arrays composed of hyaluronic acid and placed on skin allografts can locally deliver immunomodulators and simultaneously sample immune cells in interstitial fluid to monitor the response to the therapy. Using an allogeneic skin transplantation model, the microneedle‐mediated local delivery of the chemokine CCL22 and the cytokine IL‐2 is shown to increase local immune suppression in the allograft.
Design of an HA‐based MN platform for non‐invasive immunoregulation in skin transplants and immunosurveillance. A) Use of a novel HA‐based MN platform that allows for: 1) delivery of immunomodulators for the recruitment of endogenous and adoptively transferred regulatory T cells, and 2) in situ cell sampling for monitoring the Treg homing process. B) HA‐based MN fabrication process. HA‐based MNs were fabricated by casting an aqueous amine‐modified HA (HA‐SS‐NH2) solution into the PDMS mold by centrifugation and crosslinked using the NHS‐terminated 8‐arm PEG crosslinker. Chemokines were loaded and a PLGA back layer was added (top scheme). Chemical structure of the HA‐SS‐NH2 crosslinked with NHS‐terminated 8‐arm PEG forming a digestible HA hydrogel through a disulfide bond (bottom scheme). C) Degradation of the MNs under reducing conditions enables facile recovery of retrieved cells. Disulfide bonds of the HA‐based MNs are cleaved with 10 mm TCEP.
Design of an HA‐based MN platform for non‐invasive immunoregulation in skin transplants and immunosurveillance. A) Use of a novel HA‐based MN platform that allows for: 1) delivery of immunomodulators for the recruitment of endogenous and adoptively transferred regulatory T cells, and 2) in situ cell sampling for monitoring the Treg homing process. B) HA‐based MN fabrication process. HA‐based MNs were fabricated by casting an aqueous amine‐modified HA (HA‐SS‐NH2) solution into the PDMS mold by centrifugation and crosslinked using the NHS‐terminated 8‐arm PEG crosslinker. Chemokines were loaded and a PLGA back layer was added (top scheme). Chemical structure of the HA‐SS‐NH2 crosslinked with NHS‐terminated 8‐arm PEG forming a digestible HA hydrogel through a disulfide bond (bottom scheme). C) Degradation of the MNs under reducing conditions enables facile recovery of retrieved cells. Disulfide bonds of the HA‐based MNs are cleaved with 10 mm TCEP.
… 
HA‐modified hydrogel MNs present high swelling capacity, robust mechanical properties, and on‐demand degradation. A) Swelling rate of the HA‐based hydrogels composed of amine‐modified HA polymer crosslinked with NHS‐terminated 8‐arm PEG crosslinkers differing in molecular weight. B) Stained skin graft following ex vivo HA‐SS‐NH2‐derived MN application confirms skin penetration. Scale bar = 2mm. C) Detail of mouse skin after in vivo administration of hydrogel MNs. Scale bar = 2mm. D) On‐demand digestion of hydrogel disks using varying concentrations of the reducing agent, TCEP. E) Optical microscopy images of hydrogel‐based MNs before (top) and after (bottom) digestion under reducing conditions. Scale bar = 500 µm. Data are represented as mean ± s.d. (n = 3).
HA‐modified hydrogel MNs present high swelling capacity, robust mechanical properties, and on‐demand degradation. A) Swelling rate of the HA‐based hydrogels composed of amine‐modified HA polymer crosslinked with NHS‐terminated 8‐arm PEG crosslinkers differing in molecular weight. B) Stained skin graft following ex vivo HA‐SS‐NH2‐derived MN application confirms skin penetration. Scale bar = 2mm. C) Detail of mouse skin after in vivo administration of hydrogel MNs. Scale bar = 2mm. D) On‐demand digestion of hydrogel disks using varying concentrations of the reducing agent, TCEP. E) Optical microscopy images of hydrogel‐based MNs before (top) and after (bottom) digestion under reducing conditions. Scale bar = 500 µm. Data are represented as mean ± s.d. (n = 3).
… 
Characterization of MN‐based platform for chemokine delivery and immune cell sampling in vitro. A) Release of IL‐2 from the HA‐based hydrogels was quantified by tracking the fluorescence signal of the labeled IL‐2 over time. B) Analysis of the MNs loading capacity by means of fluorescence quantification (plotted as initially loaded mass of IL‐2 versus recovered mass of IL‐2, R² = 0.9987). C) Comparison of Treg migration as a function of CCL22 concentration when soluble or MN‐loaded D) Analyte recovery (RhoB) from mimetic skins with HA‐derived MNs. Detected RhoB concentration compared to the real RhoB concentration in HA‐based MNs, R² = 0.9929. E) Recovered immune cells from digested HA‐based MNs as quantified by flow cytometry. Data is represented as mean ± s.d. (n = 3). Multiple comparisons among groups were determined using either one‐way ANOVA followed by a post‐hoc test or non‐parametric t‐test (Mann‐Whitney) when applicable. P‐value: ns = not significant, *p < 0.05, **p < 0.01.
Characterization of MN‐based platform for chemokine delivery and immune cell sampling in vitro. A) Release of IL‐2 from the HA‐based hydrogels was quantified by tracking the fluorescence signal of the labeled IL‐2 over time. B) Analysis of the MNs loading capacity by means of fluorescence quantification (plotted as initially loaded mass of IL‐2 versus recovered mass of IL‐2, R² = 0.9987). C) Comparison of Treg migration as a function of CCL22 concentration when soluble or MN‐loaded D) Analyte recovery (RhoB) from mimetic skins with HA‐derived MNs. Detected RhoB concentration compared to the real RhoB concentration in HA‐based MNs, R² = 0.9929. E) Recovered immune cells from digested HA‐based MNs as quantified by flow cytometry. Data is represented as mean ± s.d. (n = 3). Multiple comparisons among groups were determined using either one‐way ANOVA followed by a post‐hoc test or non‐parametric t‐test (Mann‐Whitney) when applicable. P‐value: ns = not significant, *p < 0.05, **p < 0.01.
… 
Delivery of HA‐based MNs loaded with CCL22 and IL‐2 to skin allografts results in increased Treg recruitment. A) Study design of skin allograft transplant model. 10 mm x15 mm skin patch from BALB/cJ was transplanted onto the dorsal trunk of a Rag−/− mouse on C57BL/6 background. On day 6 post‐transplant, T lymphocytes were adoptively transferred and MNs were next applied consecutively for 5 days. On day 7 post adoptive transfer, allografts were harvested and analyzed by RT‐PCR. (n = 4 to 6 biological replicates per condition, 2 separate experiments) B) Quantification of FOXP3 to CD3 gene expression by RT‐PCR C) Intragraft Treg proliferation was assessed by IHC using FOXP3 as Treg differential biomarker. Scale bar = 100 µm. D) Quantification of the fold change in IL‐6 gene expression by RT‐PCR. E) Quantification and representative flow‐cytometry‐dot‐plot of the number of Tregs (FOXP3⁺; CD4⁺) per million of splenocytes. Multiple comparisons among groups were determined using either one‐way ANOVA followed by a post‐hoc or non‐parametric t‐test (Mann‐ Whitney) when applicable. P‐value: ns = not significant, *p < 0.05, **p < 0.01, **p < 0.001
Delivery of HA‐based MNs loaded with CCL22 and IL‐2 to skin allografts results in increased Treg recruitment. A) Study design of skin allograft transplant model. 10 mm x15 mm skin patch from BALB/cJ was transplanted onto the dorsal trunk of a Rag−/− mouse on C57BL/6 background. On day 6 post‐transplant, T lymphocytes were adoptively transferred and MNs were next applied consecutively for 5 days. On day 7 post adoptive transfer, allografts were harvested and analyzed by RT‐PCR. (n = 4 to 6 biological replicates per condition, 2 separate experiments) B) Quantification of FOXP3 to CD3 gene expression by RT‐PCR C) Intragraft Treg proliferation was assessed by IHC using FOXP3 as Treg differential biomarker. Scale bar = 100 µm. D) Quantification of the fold change in IL‐6 gene expression by RT‐PCR. E) Quantification and representative flow‐cytometry‐dot‐plot of the number of Tregs (FOXP3⁺; CD4⁺) per million of splenocytes. Multiple comparisons among groups were determined using either one‐way ANOVA followed by a post‐hoc or non‐parametric t‐test (Mann‐ Whitney) when applicable. P‐value: ns = not significant, *p < 0.05, **p < 0.01, **p < 0.001
… 
Monitoring the Treg homing process using HA‐based MNs. A) Scheme of immune cell sampling using HA‐based MNs or whole allograft biopsy. On day 7 post adoptive T cell transfer, MNs were harvested along with skin allografts (n = 4 to 6 biological replicates per condition, 2 separate experiments). MNs were digested under reducing conditions and allografts enzymatically. Cells were next stained and analyzed by flow cytometry. CD8⁺, CD4⁺, and FOXP3⁺ representative flow cytometry dot plots from B) retrieved ISF and C) skin allografts.
Monitoring the Treg homing process using HA‐based MNs. A) Scheme of immune cell sampling using HA‐based MNs or whole allograft biopsy. On day 7 post adoptive T cell transfer, MNs were harvested along with skin allografts (n = 4 to 6 biological replicates per condition, 2 separate experiments). MNs were digested under reducing conditions and allografts enzymatically. Cells were next stained and analyzed by flow cytometry. CD8⁺, CD4⁺, and FOXP3⁺ representative flow cytometry dot plots from B) retrieved ISF and C) skin allografts.
… 
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2100128 (1 of 12)
ReseaRch aRticle
Microneedle-Based Local Delivery of CCL22 and IL-2
Enriches Treg Homing to the Skin Allograft and Enables
Temporal Monitoring of Immunotherapy Ecacy
Núria Puigmal, Pere Dosta, Zhabiz Solhjou, Karim Yatim, Cynthia Ramírez,
John Y. Choi, Juliano B. Alhaddad, Ana Paula Cosme, Jamil Azzi,* and Natalie Artzi*
Skin allografts only serve as temporary dressing for patients suering
major burns due to their high immunogenicity and rejection by the immune
system, requiring systemic immunosuppressive therapies that lead to
deleterious side eects. Microneedle arrays composed of hyaluronic acid
(HA) and placed on skin allografts can locally deliver immunomodulators
and simultaneously sample immune cells in interstitial fluid to monitor the
response to the therapy. The cells can be retrieved from the microneedles
for downstream analysis by degrading the HA using a reducing agent.
Using an allogeneic skin transplantation model, it is shown that the
microneedle-mediated local delivery of the chemokine CCL22 (to attract
Tregs) and the cytokine IL-2 (to promote their expansion) increases the local
immune suppression in the allograft. Moreover, immune cell population
in the allograft correlates with that seen in the microneedles. The delivery
and sampling functions of the microneedle arrays can help regulate the
immune system locally, without inducing systemic immune suppression,
and facilitate the monitoring of the response to the therapy following skin
transplantation.
DOI: 10.1002/adfm.202100128
1. Introduction
The skin is a complex organ that has evolved to protect the host
from external insults. An intricate network of immune cells
residing in the skin is crucial for host defense, wound healing,
as well as for maintaining tissue homeostasis.[] In the event
of a challenge such as a burn, autoimmune disease, or foreign
N. Puigmal, Dr. P. Dosta, C. Ramírez, A. P. Cosme, Prof. N. Artzi
Institute for Medical Engineering and Science
Massachusetts Institute of Technology
Cambridge, MA , USA
E-mail: nartzi@bwh.harvard.edu
N. Puigmal, Dr. P. Dosta, C. Ramírez, A. P. Cosme, Prof. J. Azzi,
Prof. N. Artzi
Department of Medicine
Division of Engineering in Medicine
Brigham and Women’s Hospital
Harvard Medical School
 Landsdowne Street, Cambridge, MA , USA
E-mail: jazzi@bwh.harvard.edu
The ORCID identification number(s) for the author(s) of this article
can be found under https://doi.org/./adfm..
N. Puigmal
Grup d’Enginyeria de Materials (GEMAT)
Institut Químic de Sarrià
Universitat Ramon Llull
Via Augusta , Barcelona , Spain
Dr. Z. Solhjou, Dr. J. Y. Choi, Dr. J. B. Alhaddad, Prof. J. Azzi
Department of Medicine
Division of Renal Medicine
Brigham and Women’s Hospital
Harvard Medical School
 Longwood Avenue, Boston, MA , USA
Dr. K. Yatim
Department ofMedicine
Division of General Internal Medicine and Primary Care
Brigham and Women’s Hospital
Harvard Medical School
 Longwood Avenue, Boston, MA , USA
organ transplantation, dermal immune
cells can detect danger signals and resolve
inflammation. CD+CD+FOXP+ regu-
latory T cells (Tregs) are a subtype of T cells
that suppress other activated immune
cells and control the body’s response to
self- and foreign-antigens, in order to
prevent overactivated immune responses
such as in the case of autoimmune disor-
ders.[] Tregs account for one of the largest
subsets of immune cells in the skin, pro-
moting local immunological homeostasis
and restoring normal function after a
threat.[,] The increased proportion of Tregs
in skin-resident CD+ T cell population
compared to other organs (% in skin
vs % in peripheral blood) also suggests
an integral role for immune regulation in
a tissue-specific manner.[,] Indeed, dis-
ruption in skin Treg homeostasis—due to
dysregulated Treg number or function—
triggers disorders such as psoriasis,[]
alopecia areata,[,] diuse systemic sclero-
derma, atopic dermatitis, or cutaneous lupus erythematosus.[]
Hence, pharmacologic Treg augmentation and adoptive Treg
transfer have emerged as means to manage autoimmune disor-
ders and skin transplantation.
Skin allograft transplantation (from a genetically dierent
individual) is the first-line therapy for severe burn patients and
victims of traumatic injuries when autograft transplantation
Adv. Funct. Mater. 2021, 31, 
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... Future designs of degradable microneedles may facilitate the possibility of cell recovery for analysis. [39,[57][58][59] The primary materials used to make HPMN include PLGA and heparin which are biocompatible and already being used clinically. We acknowledge that additional testing is necessary for future studies to facilitate clinical translation. ...
... HPMN Extracts and Recovers MCP-1/Monocytes Using a Hydrogel Model: The model made of 1.4% agarose hydrogel mimicking the mechanical properties of skin was used to evaluate the ability of HPMN to sequester and recover MCP-1 and monocytes. [38,39] For testing MCP-1, HPMN was penetrated into the agarose hydrogel containing 10, 50, 100, 500, or 1000 ng mL −1 MCP-1 and incubated for 24 h, after that, the HPMN was taken out, washed with PBS for 5 min, and then soaked in 1% Triton X-100 medium for another 5 min, MCP-1 in the soaking medium was detected by ELISA assay. For testing monocytes, HPMN was incubated with the agarose hydrogel containing 10 ng mL −1 of MCP-1 and 10 3 , 10 4 , or 10 5 cells per mL of freshly isolated CellTrace CFSE labeled monocytes for 24 h, then the monocytes extracted HPMN were soaked in PBS for 2 h under gentle shaking and then the recovered cells were counted by flow cytometry (Attune NxT, Thermo Fisher). ...
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Osmosis‐Powered Hydrogel Microneedles for Microliters of Skin Interstitial Fluid Extraction within Minutes
Article
Full-text available
  • Apr 2020
Hydrogel microneedle patch enables the extraction of skin interstitial fluid (ISF) through in situ swelling in a minimally invasive manner without assistance of mechano‐chemical peripherals. However, existing hydrogel microneedles require tens of minutes with multistep process to collect sufficient volume (1 mL) for effective analysis. This study introduces an osmolyte‐powered hydrogel microneedle patch that can extract ISF three times faster than the existing platforms and provide in situ analysis of extracted biomarkers. The microneedle patch is composed of osmolytes (i.e., maltose) and hydrogel (i.e., methacrylated hyaluronic acid). During the extraction process, the osmolytes dissolve in the matrix and provide the osmotic pressure that increases the diffusion of ISF from skin to the hydrogel matrix. A patch with 100 microneedles can extract 7.90 µL of ISF from pig skin ex vivo and 3.82 µL of ISF from mouse skin in vivo within 3 min, whereas the control (i.e., hydrogel microneedle without osmolytes) requires >10 min to achieve similar results. The extracted ISF allows the quantification of biomarkers such as glucose and/or drugs such as insulin in vivo. Through the integration with the electronic glucose sensors, the whole system permits the direct and rapid analysis of the extracted glucose.
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In situ recruitment of regulatory T cells promotes donor-specific tolerance in vascularized composite allotransplantation
Article
Full-text available
  • Mar 2020
Vascularized composite allotransplantation (VCA) encompasses face and limb transplantation, but as with organ transplantation, it requires lifelong regimens of immunosuppressive drugs to prevent rejection. To achieve donor-specific immune tolerance and reduce the need for systemic immunosuppression, we developed a synthetic drug delivery system that mimics a strategy our bodies naturally use to recruit regulatory T cells (T reg ) to suppress inflammation. Specifically, a microparticle-based system engineered to release the T reg -recruiting chemokine CCL22 was used in a rodent hindlimb VCA model. These “Recruitment-MP” prolonged hindlimb allograft survival indefinitely (>200 days) and promoted donor-specific tolerance. Recruitment-MP treatment enriched T reg populations in allograft skin and draining lymph nodes and enhanced T reg function without affecting the proliferative capacity of conventional T cells. With implications for clinical translation, synthetic human CCL22 induced preferential migration of human T reg in vitro. Collectively, these results suggest that Recruitment-MP promote donor-specific immune tolerance via local enrichment of suppressive T reg .
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Gelatin Methacryloyl Microneedle Patches for Minimally Invasive Extraction of Skin Interstitial Fluid
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The extraction of interstitial fluid (ISF) from skin using microneedles (MNs) has attracted growing interest in recent years due to its potential for minimally invasive diagnostics and biosensors. ISF collection by absorption into a hydrogel MN patch is a promising way that requires the materials to have outstanding swelling ability. Here, a gelatin methacryloyl (GelMA) patch is developed with an 11 × 11 array of MNs for minimally invasive sampling of ISF. The properties of the patch can be tuned by altering the concentration of the GelMA prepolymer and the crosslinking time; patches are created with swelling ratios between 293% and 423% and compressive moduli between 3.34 MPa and 7.23 MPa. The optimized GelMA MN patch demonstrates efficient extraction of ISF. Furthermore, it efficiently and quantitatively detects glucose and vancomycin in ISF in an in vivo study. This minimally invasive approach of extracting ISF with a GelMA MN patch has the potential to complement blood sampling for the monitoring of target molecules from patients.
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A Hydrogel Microneedle Patch for Point‐of‐Care Testing Based on Skin Interstitial Fluid
Article
Full-text available
  • Jan 2020
Skin interstitial fluid (ISF) holds great potential as a highly desirable sample resource for point‐of‐care testing (POCT), where the key is to effectively collect target biomarkers from ISF. Hydrogel microneedle patch has great promise for ISF extraction. However, it is challenging to recover target biomarkers from the extracted skin ISF in hydrogel microneedle patches in an easy‐administrated, fast, and bulky instrument‐free manner. Herein, a hydrogel microneedle patch made of polyvinyl alcohol (PVA) and chitosan (CS) for POCT based on the ISF is developed. The phase transition property of PVA/CS hydrogel makes the microneedles stiff when dry, which is beneficial to easily penetrate into skin. Meanwhile, the highly porous microstructure of hydrogel offers good swelling ability for extraction of ISF and the thermal degradation property of PVA makes it convenient to quickly and efficiently recover target biomarkers from microneedle patch. The capability of this platform for POCT applications is further demonstrated by successful detections of typical biomarkers collected from the mimetic skin and monitoring the glucose level in rabbit skins during a day. The developed hydrogel microneedle patch holds the advantages of extraction of skin ISF and recovery of biomarkers, thus presenting as a powerful platform for skin ISF‐based POCT applications.
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Nanomedicine‐Based Immunotherapy for the Treatment of Cancer Metastasis
Article
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Metastasis is the leading cause of cancer‐associated death, with poor prognosis even after extensive treatment. The dormancy of metastatic cancer cells during dissemination or after colony formation is one major reason for treatment failure, as most drugs target cells of active proliferation. Immunotherapy has shown great potential in cancer therapy because the activity of effector cells is less affected by the metabolic status of cancer cells. In addition, metastatic cells out of immunosuppressive tumor microenvironment (TME) are more susceptible to immune clearance, although these cells can achieve immune surveillance evasion via strategies such as platelet and macrophage recruitment. Since nanomaterials themselves or their carried drugs have the capability to modulate the immune system, a great amount of focus has been placed on nanomedicine strategies that leverage immune cells participating the metastatic cascade. These nanomedicines successfully inhibit the tumor metastasis and prolong the survival of model animals. Immune cells that are involved in the metastasis cascade are first summarized and then recent and inspiring strategies and nanomaterials in this growing field are highlighted. Recent advances in nanomedicine‐based immunotherapy for the treatment of cancer metastasis are reviewed, starting with a brief introduction of metastasis cascade and nanomedicine‐based cancer immunotherapy. Recent strategies that can modulate key immune cells participating in metastasis cascade including cell intravasation and extravasation, blood circulation, and micrometastatic colony formation and proliferation are summarized.
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Sampling interstitial fluid from human skin using a microneedle patch
Article
  • Nov 2020
Tissue interstitial fluid (ISF) surrounds cells and is an underutilized source of biomarkers that complements conventional sources such as blood and urine. However, ISF has received limited attention due largely to lack of simple collection methods. Here, we developed a minimally invasive, microneedle-based method to sample ISF from human skin that was well tolerated by participants. Using a microneedle patch to create an array of micropores in skin coupled with mild suction, we sampled ISF from 21 human participants and identified clinically relevant and sometimes distinct biomarkers in ISF when compared to companion plasma samples based on mass spectrometry analysis. Many biomarkers used in research and current clinical practice were common to ISF and plasma. Because ISF does not clot, these biomarkers could be continuously monitored in ISF similar to current continuous glucose monitors but without requiring an indwelling subcutaneous sensor. Biomarkers distinct to ISF included molecules associated with systemic and dermatological physiology, as well as exogenous compounds from environmental exposures. We also determined that pharmacokinetics of caffeine in healthy adults and pharmacodynamics of glucose in children and young adults with diabetes were similar in ISF and plasma. Overall, these studies provide a minimally invasive method to sample dermal ISF using microneedles and demonstrate human ISF as a source of biomarkers that may enable research and translation for future clinical applications.
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Regulatory T cells engineered with TCR signaling-responsive IL-2 nanogels suppress alloimmunity in sites of antigen encounter
Article
  • Nov 2020
Adoptive cell transfer of ex vivo expanded regulatory T cells (T regs) has shown immense potential in animal models of auto-and alloimmunity. However, the effective translation of such T reg therapies to the clinic has been slow. Because T reg homeostasis is known to require continuous T cell receptor (TCR) ligation and exogenous interleukin-2 (IL-2), some investigators have explored the use of low-dose IL-2 injections to increase endogenous T reg responses. Systemic IL-2 immunotherapy, however, can also lead to the activation of cytotoxic T lymphocytes and natural killer cells, causing adverse therapeutic outcomes. Here, we describe a drug delivery platform, which can be engineered to autostimulate T regs with IL-2 in response to TCR-dependent activation, and thus activate these cells in sites of antigen encounter. To this end, protein nanogels (NGs) were synthesized with cleavable bis(N-hydroxysuccinimide) cross-linkers and IL-2/Fc fusion (IL-2) proteins to form particles that release IL-2 under reducing conditions, as found at the surface of T cells receiving stimulation through the TCR. T regs surface-conjugated with IL-2 NGs were found to have preferential, allograft-protective effects relative to unmodified T regs or T regs stimulated with sys-temic IL-2. We demonstrate that murine and human NG-modified T regs carrying an IL-2 cargo perform better than conventional T regs in suppressing alloimmunity in murine and humanized mouse allotransplantation models. In all, the technology presented in this study has the potential to improve T reg transfer therapy by enabling the regulated spatiotemporal provision of IL-2 to antigen-primed T regs .
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Hyaluronic Acid Dissolving Microneedle Patch Loaded with Methotrexate for Improved Treatment of Psoriasis
Article
  • Oct 2019
Methotrexate (MTX) is one of the first-line treatments for moderate to severe psoriasis, while the side effects caused by injection and oral administration of MTX greatly restrict its clinical application. Transdermal drug delivery offers a desirable alternative to the conventional approaches, but the performances of current available skin penetration enhancement techniques are not so satisfactory. To address these limitations, we developed a dissolving microneedle (MN) patch made of hyaluronic acid (HA) with excellent water-solubility, biocompatibility, biodegradability and mechanical property. The amount of MTX encapsulated in the needles of the patch could be controlled during fabrication process for precise dosage. Interestingly, the MTX-loaded MNs successfully penetrated imiquimod (IMQ)-induced thickened epidermis in mice and delivered the drug intralesionally. Meanwhile, fast dissolution of HA endowed the MNs with operability for patients. We found the MTX-loaded MNs not only showed well-maintained inhibitory effect in vitro but also alleviated the psoriasis-like skin inflammation in mice. Moreover, the MTX-loaded MNs were significantly more efficacious than taking the same dose of drug orally. Consequently, a higher oral dose of MTX was required for a comparable amelioration, which in turn increased its systemic toxicity. Taken together, the proposed MTX-loaded dissolving MN patch strategy provides new opportunity for efficient and safe treatment of psoriasis.
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