Collagens Regulating Adipose Tissue Formation and Functions.

The globally increasing prevalence of obesity is associated with the development of metabolic diseases such as type 2 diabetes, dyslipidemia, and fatty liver. Excess adipose tissue (AT) often leads to its malfunction and to a systemic metabolic dysfunction because, in addition to storing lipids, AT is an active endocrine system. Adipocytes are embedded in a unique extracellular matrix (ECM), which provides structural support to the cells as well as participating in the regulation of their functions, such as proliferation and differentiation. Adipocytes have a thin pericellular layer of a specialized ECM, referred to as the basement membrane (BM), which is an important functional unit that lies between cells and tissue stroma. Collagens form a major group of proteins in the ECM, and some of them, especially the BM-associated collagens, support AT functions and participate in the regulation of adipocyte differentiation. In pathological conditions such as obesity, AT often proceeds to fibrosis, characterized by the accumulation of large collagen bundles, which disturbs the natural functions of the AT. In this review, we summarize the current knowledge on the vertebrate collagens that are important for AT development and function and include basic information on some other important ECM components, principally fibronectin, of the AT. We also briefly discuss the function of AT collagens in certain metabolic diseases in which they have been shown to play central roles.

The healing effect of Wharton's jelly stem cells seeded on biological scaffold in chronic skin ulcers: A randomized clinical trial.

BACKGROUND: Chronic wound or nonhealing ulcer is essentially a wound that does not progress normally through the wound healing process. This study assessed the healing effect of umbilical cord Wharton's jelly stem cells seeded on biological scaffold in chronic skin ulcers. MATERIALS AND METHODS: In a randomized clinical trial, five patients between 30 and 60 years with chronic diabetic wounds were enrolled. To cover the wounds, acellular amniotic membrane seeded with Wharton's jelly mesenchymal stem cells (WJSCs) was used for 9 days, every 3 days with a follow-up of 1 month. The percentage and time of wound healing and the size of wound were recorded for each patient. RESULTS: In treated patients, the wound healing time and wound size significantly decreased, and after 6 and 9 days, the wound size significantly declined (P < 0.002). CONCLUSION: As WJSCs seeded on amniotic membrane could significantly accelerate the healing effect in chronic diabetic wounds, they can be an alternative source in tissue engineering and repair of chronic ulcers.

Biochemical Methods in Production of Three-Dimensional Scaffolds from Human Skin: A Window in Aesthetic Surgery.

BACKGROUND: Use of matrix-derived biologic scaffolds has become a treatment of choice in several clinical issues. This study assessed biochemical methods in production of three-dimensional scaffolds from human skin. METHODS: Human skin was prepared from circumcisions, washed in phosphate buffer saline (PBS) and kept at -20ºC until use. The skin samples underwent various methods. In group A, NaCl, Triton X100 and EDTA solution were used for removal of epidermis and was subdivided to three subgroups. The solution for removal of epidermis was similar for all subgroups, but decellularization was different. Group B was subdivided into 6 subgroups, NaCl in different concentrations was used for removal of epidermis and decellularization happened using SDS in various concentrations and different time intervals. Group C was subdivided to 3 subgroups, trypsin was used for removal of epidermis and decellularization was conducted applying NaOH or SDS. Washing was performed using only PBS. In group D, decellularization was done applying SDS. Histomorphometric study was conducted to compare the groups. RESULTS: No fibroblast was present in A2, B2, B4, and C3 subgroups after decellularization. Histological photographs from subgroups A1 to A3 revealed several cells and collagen fibers. Dense collagen fibers in pink color were noted in all subgroups; but, epidermis was absent. CONCLUSION: It was shown that 1M NaCl was the best solution for removal of epidermis, 0.5% SDS for 2 h was the most effective solution for decellularization and PBS was the best solution for washing, while the solutions are easily available and cost-effective.

Co-condensation synthesis of well-defined mesoporous silica nanoparticles: effect of surface chemical modification on plasmid DNA condensation and transfection.

Chemically modified mesoporous silica nanoparticles (MSNs) are of interest due to their chemical and thermal stability with adjustable morphology and porosity; therefore, it was aimed to develop and compare the MCM-41 MSNs functionalised with imidazole groups (MCM-41-Im) to unmodified (MCM-41-OH) and primary amine functionalised (MCM-41-NH2) MSNs for experimental gene delivery. The results show efficient transfection of the complexes of the plasmid and either MCM-41-NH2 or MCM-41-Im. Furthermore, following transfection of HeLa cells using MCM-41-Im, an enhanced GFP expression was achieved consistent with the noticeable DNase1 protection and endosomal escape properties of MCM-41-Im using carboxyfluorescein tracer.

The Role of Human Adult Peripheral and Umbilical Cord Blood Platelet-Rich Plasma on Proliferation and Migration of Human Skin Fibroblasts.

BACKGROUND: Wound healing is a complex and dynamic process following damage in tissue structures. Due to extensive skin damage caused by burn injuries, this study determined the role of human adult peripheral and umbilical cord blood platelet-rich plasma on proliferation and migration in human skin fibroblasts. METHODS: Platelet-rich plasma (5, 10, 15, 20 and 50% PRP) from human umbilical cord blood and adult peripheral blood were provided and added to fibroblasts cultured from a human skin sample. Migration and proliferation of fibroblasts were assessed in comparison to 10% FBS and by the fibroblast responses to a concentration gradient. RESULTS: All components of the umbilical cord blood PRP significantly stimulated the growth of fibroblasts when compared to the negative control. Fibroblast growth was enhanced in a dose dependent manner. All fibroblast cultures retained normal morphology. No significant difference was noted between umbilical cord blood and adult peripheral blood PRP preparations regarding cell proliferation and migration, but the difference to 10% FBS was significant. 1% and 50% PRP reduced cellular proliferation. The 20% umbilical cord blood PRP and 10% adult peripheral blood PRP had a significant stimulatory effect on the migration of the skin fibroblast cells in comparison with 10% FBS. CONCLUSION: As PRP could promote the migration and proliferation of dermal fibroblasts, it can be safely added in cultures when treatment of chronic wounds without triggering the immune response is needed.