Papers by Keyword: Acellular Dermal Matrix

Abstract: A new antibacterial acellular dermal matrix (AADM) dressing can not only resist infection, but also accelerate wound healing. AADM was prepared by SDS (0.40%), trypsin (0.40%) and keratin (0.30%), and then cross-linked with carboxymethyl chitosan (1%) with glutaraldehyde, whose tensile strength (MPa) is 10.66, thickness (mm), 0.53, the rate of permeable steam (g • m^-2 • 24h^-1), 3640, porosity (%), 81, degradation time in vitro (h), 24.33, pH, 6.5, and the average inhibition rate, more than 70%. At the same time, scanning electron microscopy showed that the structure of AADM was evacuated and the pores were interconnected. On such basis, a conclusion was drawn: the properties of AADM has been sharply increased, compared with acellular dermal matrix, which cannot resist infection, and the new antibacterial acellular dermal matrix completely meets the clinical requirements for burn dressings.

Abstract: A porcine ADM was prepared by the means of combined treatments with alkali, enzymes, sodium lauryl sulfate (SDS) and NaCl solution. Concentration and process time of enzymes were varied respectively, and their effects on properties of ADM were evaluated, such as porosity, mechanical properties, enzymatic degradation. The composition of ADM was detected with an amino acid analyzer, and its microstructure was observed under SEM. To estimate its cytocompatibility, cells proliferation tests were performed by MTT assay, and cells distribution was viewed under CLSM. With increase of enzymes concentration and process time, the porosity of ADM was enhanced, but its ultimate tensile strength was weakened. And enzymatic process time affected the degradation rate of ADM in collagenase solution greatly. The obtained ADM framework had interconnected pores at about 100 μm in diameter. The MTT assay and CLSM image indicated that cells cultured on ADM proliferated well and distributed evenly. The prepared ADM has good microstructure, high mechanical properties, controlled enzymatic stability and good cell compatibility, and it has great potential use in the tissue engineering for further study.

Abstract: The determination of aldehyde in genipin(GP) was carried out through solution silver mirror reaction and curpous oxide reaction. Influence of various dosage, pH, temperature and reaction time on shrinkage temperature of GP-crosslinked porcine acellular dermal matrix (GP-pADM) were investigated. The cytotoxicity and cell morphology of GP-pADM were observed. The results reveal that the existence of aldehyde is proved by silver mirror reaction and curpous oxide reaction. With increasing dosage of GP, shrinkage temperature of pADM increase. And with increasing pH, temperature and time, shrinkage temperature exhibit an early ascending trend and then decline slightly. Cytotoxicity of GP-pADM is 0 grade with great morphology, cell L929 could adhesive grow on the surface and in the pore of this material. The implications of all this are that GP is an ideal biological crosslinking agent for biomaterials.

Abstract: Porcine acellular dermal matrix (pADM) was modified by N-(2-Hydroxy) propyl-3-Trimethyl Ammonium Chitosan Chloride (HTCC) with varied concentration, pH, time and temperature. The absorption of HTCC, surface state, hydrophilicity, antibacterial properties and cytotoxicity of pADM were researched before and after modification. Results show that the optimum experimental condition of modification is pH 6.4, 37°C, treated for 48 hours, and the concentration of HTCC 0.7%. The contact angle of modified pADM reduces and the water absorption ratio increases, but the tensile strength and moisture permeability falls. Obvious antibacterial action is observed on Escherichia Coli and Staphylococcus Aureus, and cytotoxicity is grade 2. This work suggests the feasibility of HTCC to modify pADM.

Abstract: The development of skin tissue engineering provides a noninvasive method for skin restoration. Unfortunately, the lack of a vascular plexus leads to greater time for vascularization compared with native skin autografts and contributes to graft failure. Our purpose was to construct tissue-engineered skin with VEGF- modified human bone marrow mesenchymal stem cells (hMSCs) as well as acellular dermal matrix(ADM) in vitro , Thus by increased vascular endothelial growth factor expression, which could prospectively improve vascularization of tissue-engineered skin for wound healing applications. To reach this aim, hMSCs were isolated and cultured with density gradient centrifugation combined with attachment culture method in vitro. Liposome- mediated gene transfer was used to generate a population of hMSCs overexpressing the gene encoding VEGF165. Then VEGF- modified hMSCs were seeded onto the surface of ADM. The experimental results showed that ADM we prepared has good compatibility with MSCs, the cells in ADM grew and proliferated well in vitro and the tissue - engineered skin with VEGF- modified hMSCs and ADM has been successfully constructed.

Abstract: In theory, Ultraviolet (UV)-generated free radicals can expedite Acellular dermal matrix (ADM) crosslinking with glucose via the formation of reactive, linear glucose molecules. The aim of this study is to maintain strength and stability of UV-irradiated ADM without the introduction of cytotoxic chemical crosslinkers. The strength and stability changes of ADM by UV-irradiated with glucose (GLUC) were investigated under various conditions. ADM strength and stability were determined by tensile testing, differential scanning calorimetry (DSC), and swelling ratio. After exposure to UV-irradiation, ADM containing glucose revealed different mechanical properties compare to ADM without glucose, greater resistance to enzymatic degradation, and higher heatdenatured breaking loads. DSC explained that glucose-incorporated ADM sterilized by UVirradiation decreased peak width (Tpeak-Ts) compared to one another. On the other hand, Area (J/g) and Ts increased glucose-incorporated ADM. The exposure of ADM to UV caused significant increase in hydration, but a significant decrease in the swelling ratio compared with the nonirradiated ADM. These data strongly suggests that free radical-dependent, glucose-derived crosslinks provide enhanced strength and enzyme resistance in glucose-incorporated, UV-exposed ADM.