[show abstract][hide abstract] ABSTRACT: The emergence of skin substitutes provides a new approach for the treatment of wound repair and healing. The consistent and steady release of angiogenic factors is an important factor in the promotion of angiogenesis in skin substitutes, which usually lack, yet need, a vascular network.
In this study, ginsenoside Rg1, a natural compound isolated from Panax notoginseng (PNS), was incorporated into a collagen/chitosan-gelatin microsphere (CC-GMS) scaffold. The cumulative release kinetics were evaluated, and the effects of the released Rg1 on human umbilical vein endothelial cells (HUVECs) behavior, including proliferation, migration, tube formation, cell-cycle progression, cell apoptosis, and vascular endothelial growth factor (VEGF) secretion, were investigated. Additionally, HUVECs were cultured on the CC-GMS scaffold to test its biocompatibility. Standard Rg1 and VEGF were used as positive controls.
The results indicated that the CC-GMS scaffold had good release kinetics. The Rg1 released from the CC-GMS scaffold did not lose its activity and had a significant effect on HUVEC proliferation. Both Rg1 and VEGF promoted HUVEC migration and tube formation. Rg1 did not induce HUVEC apoptosis but instead promoted HUVEC progression into the S and G2/M phases of the cell cycle. Rg1 significantly increased VEGF secretion compared with that in the control group. HUVEC culture on the CC-GMS scaffold indicated that this scaffold has good biocompatibility and that CC-GMS scaffolds containing different concentrations of Rg1 promote HUVEC attachment in a dose- and time-dependent manner.
Rg1 may represent a new class of angiogenic agent that can be encapsulated in CC-GMS scaffolds to exert angiogenic effects in engineered tissue.
[show abstract][hide abstract] ABSTRACT: PURPOSE: Quantitative monitoring of the redox status is the foundation for redox-related treatment. The purpose of this study was to evaluate the reliability of a new depolarization curve method for plasma redox potential (ORP) monitoring. METHODS: Using the new method, we performed redox determinations for the first time under different sample-handling conditions, including redox titration experiments using KMnO4 and vitamin C and dynamic redox monitoring in burn patients. The relative ORP value (ΔORP) method (improved traditional method) was used as the reference. RESULTS: The new method's better reliability, electrochemical specificity and practicability, and known group validity, which are closely associated with the redox-related pathological processes of severe burns, were confirmed. Furthermore, bidirectional change in the redox status in severe burn patients was also observed for the first time. CONCLUSIONS: This simple, stable new method could be a better practical tool for making the dynamic monitoring of the redox status feasible and for providing useful quantitative information for the judgment of redox-related pathological process, thus improving corresponding individualized treatments that rely on quantitative adjustments to the redox status.
Redox report: communications in free radical research 03/2013; · 1.51 Impact Factor
[show abstract][hide abstract] ABSTRACT: To perform a retrospective survey of the clinical features and clinical courses of diabetic foot patients with amputations hospitalized in the Second Affiliated Hospital of Zhejiang University from 2007 to 2011.According to the database from the medical records department in our hospital 36 cases of diabetic patients were selected out of 805 cases of amputees. The clinical information was recorded in detail. With the contact information provided in the medical record, telephone interviews were conducted for each patient and their family to complete the record for the current disease progression and the patient's treatment process. Among all of the patients with hospitalized amputations, 36/805(4.47%) were diabetic foot patients with amputations, accounting for 36/273(13.19%) of non-traumatic amputations. The average age of the diabetic patients with first-time amputations was 62 years, the average BMI was greater than 24.5kg/m2, and the waist-to-hip ratio was greater than 0.92. Among the 22 patients who completed the follow-up interviews, 17 had only small amputations. Diabetic amputation has become a common clinical problem. The patients were mainly elderly, overweight or obese. Amputations at the toe level still accounted for a large proportion of the patients. Overall, the follow-up interviews indicated that the patients lacked good understanding of and concern for their own disease, with unclear control of blood sugar and no standardized control method. Helping the patients to understand the disease and paying attention to health education may play a role in the prevention and treatment of diabetes and diabetic foot disease.
The International Journal of Lower Extremity Wounds 08/2012; 11(3):194-200. · 1.25 Impact Factor
[show abstract][hide abstract] ABSTRACT: Nanotechnology is a highly promising field, with nanoparticles produced and utilized in a wide range of commercial products. Silver nanoparticles (AgNPs) has been widely used in clothing, electronics, bio-sensing, the food industry, paints, sunscreens, cosmetics and medical devices, all of which increase human exposure and thus the potential risk related to their short- and long-term toxicity. Many studies indicate that AgNPs are toxic to human health. Interestingly, the majority of these studies focus on the interaction of the nano-silver particle with single cells, indicating that AgNPs have the potential to induce the genes associated with cell cycle progression, DNA damage and mitochondrial associated apoptosis. AgNPs administered through any method were subsequently detected in blood and were found to cause deposition in several organs. There are very few studies in rats and mice involving the in vivo bio-distribution and toxicity, organ accumulation and degradation, and the possible adverse effects and toxicity in vivo are only slowly being recognized. In the present review, we summarize the current data associated with the increased medical usage of nano-silver and its related nano-materials, compare the mechanism of antibiosis and discuss the proper application of nano-silver particles.
[show abstract][hide abstract] ABSTRACT: Mechanical properties are essential considerations for the design of porous scaffolds in the field of tissue engineering. To develop a well-supported hybrid dermal substitute, poly(L-lactide-co-glycolide) (PLGA) yarns were knitted into a mesh with relative fixed loops, followed by incorporation into collagen-chitosan scaffolds (CCS) to obtain PLGA knitted mesh-reinforced CCS (PLGAm/CCS). The morphology and tensile strength in both the dry and wet state of PLGAm/CCS were investigated in vitro. To characterize the tissue response, specifically angiogenesis and tissue regeneration, PLGAm/CCS was embedded subcutaneously in Sprague-Dawley rats and compared with two control implants, i.e., PLGA mesh (PLGAm) and CCS. At weeks 1, 2, and 4 post surgery, tissue specimens were harvested for histology, immunohistochemistry, real-time quantitative PCR and Western blot analysis. These results demonstrated that the incorporation of PLGA knitted mesh into CCS can improve the mechanical strength with little influence on its mean pore size and porosity. After implantation, PLGAm/CCS can resist contraction and promote cell infiltration, neotissue formation, and blood vessel ingrowth, effectively. In conclusion, the mechanical strength of scaffolds can play a synergetic role in tissue regeneration and vascularization by maintaining its 3D microstructure. The ability of PLGAm/CCS to promote angiogenesis and induce in situ tissue formation demonstrates its strong potential in the field of skin tissue engineering.
Journal of the mechanical behavior of biomedical materials. 04/2012; 8:204-15.
[show abstract][hide abstract] ABSTRACT: A novel dermal substitute of combining recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) with a porous heparinized collagen/chitosan scaffolds was developed, considering the inadequate angiogenesis during repair of full-thickness skin defects. The physicochemical properties of heparinized collagen/chitosan scaffolds were examined and in vitro release pattern of rhGM-CSF from scaffolds was measured by ELISA. Four groups of composite scaffolds (heparinized or unheparinized scaffolds loaded with or without rhGM-CSF) were fabricated for subcutaneous implantation in young adult male Sprague-Dawley (SD) rats. Tissue specimens were harvested at different time points after implantation for histopathological, immunohistochemical observation, and Western blotting analysis. The heparinized scaffolds (H(1)E) showed slower biodegradation and sustained release of rhGM-CSF in vitro, although no significantly different release pattern was observed between the H(1)E and unheparinized scaffolds (H(0)E). In vivo investigation revealed that the heparinized scaffolds loaded with rhGM-CSF (H(1)E/rhGM-CSF) had the best cellular adhesion and migration, new vessel formation, and highest expression of VEGF and TGF-β1, indicating promoted angiogenesis. This study demonstrated that composite dermal substitute of combining rhGM-CSF with a porous heparinized collagen/chitosan scaffolds could be a potential therapeutic agent for full-thickness skin defects because of its sustained delivery of rhGM-CSF.
Journal of Biomedical Materials Research Part B Applied Biomaterials 12/2011; 100(3):788-98. · 2.31 Impact Factor
[show abstract][hide abstract] ABSTRACT: Knitting is an ancient and yet, a fresh technique. It has a history of no less than 1,000 years. The development of tissue engineering and regenerative medicine provides a new role for knitting. Several meshes knitted from synthetic or biological materials have been designed and applied, either alone, to strengthen materials for the patching of soft tissues, or in combination with other kinds of biomaterials, such as collagen and fibroin, to repair or replace damaged tissues/organs. In the latter case, studies have demonstrated that knitted mesh scaffolds (KMSs) possess excellent mechanical properties and can promote more effective tissue repair, ligament/tendon/cartilage regeneration, pipe-like-organ reconstruction, etc. In the process of tissue regeneration induced by scaffolds, an important synergic relationship emerges between the three-dimensional microstructure and the mechanical properties of scaffolds. This paper presents a comprehensive overview of the status and future prospects of knitted meshes and its KMSs for tissue engineering and regenerative medicine.
Journal of the mechanical behavior of biomedical materials. 10/2011; 4(7):922-32.
[show abstract][hide abstract] ABSTRACT: This is a work aimed to investigate the biodegradability, biocompatibility and mechanical property of the poly-lactide-co-glycolic acid (PLGA) knitted mesh preliminarily and to further explore its applications in tissue engineering and regenerative medicine. The biological property of PLGA mesh was investigated comprehensively with the degradation experiment in vitro, the acute cytotoxicity assay, the intradermal irritation test and the subcutaneous implantation test in vivo utilized. The degradation experiment in vitro demonstrated that the pH value of the removed solution fluctuated between 6.68 and 7.33. The elastic modulus of the PLGA mesh increased at first and then decreased afterwards. The acute toxicity test and the intradermal irritation test indicated that the PLGA mesh was with innocuity safety. The PLGA mesh accelerated degradation and was replaced gradually by the neotissue. The results of immunohistochemical staining demonstrated that the number of ED-1+ cells increased at first and then decreased afterwards. The PLGA mesh with excellent mechanical properties, good biocompatibility and favorable degradation ratio has the potential to be employed as a "skeleton" to reinforce the mechanical property of collagen-based dermal substitutes in tissue engineering.
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi 02/2011; 28(1):163-9.
[show abstract][hide abstract] ABSTRACT: Re-epithelialization is the first and most important step in cutaneous wound healing. The vital role of epidermal cells, or keratinocytes, in accelerating wound healing has long been established. The technique of delivering the cultured and uncultured epidermal cells to the wound bed takes a variety of forms including cultured epithelial autografts (CEAs), tissue-engineered skin equivalent, epidermal suspension and microbead-loaded composite. These techniques, together with the keratinocyte culturing method and scaling up equipment, are still the ongoing research. Application of these techniques also bears direct impact on the outcome of the wounded patients. Best understanding of the delivery technique and its relationship with the culturing method and delivery vehicle could benefit not only the wounded patient but also the development of tissue-engineered skin equivalent.
Journal of Dermatological Treatment 10/2010; 23(3):224-37. · 1.50 Impact Factor
[show abstract][hide abstract] ABSTRACT: The process of wound healing involves a complex interplay of cells, mediators, growth factors and cytokines. GM-CSF has been shown to be involved in a number of processes essential in this event. Topically applied rhGM-CSF has been reported to successfully treat wounds with diverse etiology, including burns, chronic venous leg ulcers, pressure ulcers, and leprosy ulcers, both in animal experiments and clinical studies. To evaluate the effect of the rhGM-CSF on wound healing, 8 RCT studies and 23 clinical studies and case reports are collected for analysis of the evidence. The overall effects of rhGM-CSF on the healing of wound are diverse. Topically applied rhGM-CSF is beneficial for deep partial-thickness burn wounds, chronic leg ulcers, and leprosy ulcers. rhGM-CSF may have a positive effect on other type of chronic ulcers such as pressure ulcers and cancer related ulcers, but the evidence is not sufficient for generalised use at present. rhGM-CSF is suggested have no accelerating effect on the healing of healthy wounds or surgical incisions.
Burns: journal of the International Society for Burn Injuries 10/2010; 37(5):729-41. · 1.95 Impact Factor