Objective To summarize the developmental process of biomedical materials and regenerative medicine. Methods After reviewing and analyzing the literature concerned, we put forward the developmental direction of biomedical materials and regenerative medicine in the future. Results Biomedical materials developed from the first and second-generations to the third-generation in the 1990s. Regenerative medicine was able to help the injured tissues and organs to be regenerated by the use of the capability of healing themselves. This kind of medicine included the technologies of the stem cells and the cloning, the tissue engineering, the substitute tissues and organs, xenotransplantation and soon. Conclusion The third-generation biomaterials possess the following two properties: degradation and bioactivity; and they can help the body heal itself once implanted. Regenerative medicine is a rapidly advancing field that opens a new and exciting opportunity for completely revolutionary therapeutic modalities and technologies.
Objective To review the current situation of alginate-based biomedical materials, especially focus on the clinical strategies and research progress in the clinical applications and point out several key issues that should be concerned about. Methods Based on extensive investigation of domestic and foreign alginate-based biomedical materials research and related patent, literature, and medicine producted, the paper presented the comprehensive analysis of its research and development, application status, and then put forward several new research directions which should be focused on. Results Alginate-based biomedical materials have been widely used in clinical field with a number of patients, but mainly in the fields of wound dressings and dental impression. Heart failure treatment, embolization, tissue engineering, and stem cells culture are expected to become new directions of research and products development. Conclusion Development of alginate-based new products has good clinical feasibility and necessity, but a lot of applied basic researches should be carried out in the further investigations.
Objective To investigate the effect of ultra-filtration on reducing the matrix effects of the immersionof recombination human acellular dermal matrix (rhADM) on detecting residual bovine serum albumin (BSA) by ELISA.Methods Preparation of rhADM immersion: rhADM were rinsed, and then rhADM immersion were prepared. Physiologicalsal ine was used as immersion medium. Presaturation and ultra-filtration: marked the ultra-filtration tubes as PR1 (presaturation protocol 1), PR2 (presaturation protocol 2) and rhADM, respectively, added 2 mL of 1 mg/mL and 10 μg/mL BSA solution into PR1 and PR2 respectively, and added 2 mL of rhADM immersion into rhADM tubes (rhADM1 and rhADM2). The tubes were then centrifuged at 1 500 × g for 20 minutes. The above steps were repeated for 3 times. Take the inner-tube of ultrafiltration into unused centrifuge tube. Added 4 mL of 10 μg/mL BSA solution in PR1 and PR2 tubes, 4 mL of rhADM immersion in rhADM tubes, centrifuged at 1 500 × g for 20 minutes, and then the filtration was colleted. Detecting BSA concentration: the BSA concentrations of all samples were detected by using the quantitative measure of residual BSA ELISA kit. The recoveries of 10 μg/ mL BSA solution treated by presaturation protocol 1 and 2 were calculated (untreated 10 μg/mL BSA solution was as the basic sample, marked R10 and R20 respectively). The correlation coefficient between the logarithm of the filtrate dilution and the absorbance (A) value was calculated and compared with that of water exact without ultra-filtration. Results The BSA concentration of PR1 and R10 was (23.80 ± 1.58) μg/ mL and (9.04 ± 0.24) μg/mL, respectively. The BSA concentration of PR2 and R20 was (8.64 ± 0.24) μg/mL and (8.12 ± 1.01) μg/ mL, respectively. The average recovery of 10 μg/mL BSA was 263.4% ± 16.9% and 106.5% ± 3.0% when the ultra-filtration tubes were presaturaed by PR1 and PR2 (P lt; 0.01), respectively. The BSA recovery of PR2 met the detecting demand. The correlations between A value and sample dilution were increased, the correlationcoefficient was raised from — 0.727 to — 0.960 after rhADM immersion were treated by ultra-filtration. Conclusion Theresults show that the matrix effects can be reduced effectively by ultra-filtration, indicating that an acceptable recovery of BSA can be acquired when ultra-filtration tube is presaturated by sample water extract.
Objective To investigate the method of constructing a tissue engineered epidermis with human epidermal cells and polycarbonate membrane, and to establ ish a tissue engineered epidermis with barrier function which is intended to be the replacing model in vitro of skin irritation test. Methods The tissue engineered epidermis was constructed by using polycarbonate membrane as scaffold and stratified differentiated epidermis derived from human keratinocytes. The tissue engineered epidermis was cultured on an inert polycarbonate filter at the air-liquid interface. After 13 days of culture, the composition and structure of tissue engineered epidermis were observed by HE staining, immunofluorescence staining of keratin 10 (K10) amp; K13, K14, laminin,involucrin, and filaggrin, and transmission electronic microscope. The half maximal inhibitory concentration of a substance (IC50) of SDS was determined in the penetration test of tissue engineered epidermis cultured in the absence (control group) or the presence (experimental group) of l i pid supplement for 18 hours. Results The constructed epidermis was similar to normalepidermis, which was consisted of a proliferating basal layer, differentiated spinous layer, granular layer, and stratum corneum. The IC50 values of tissue engineered epidermis cultured in the control group and experimental group were 0.072% (2.36 mmol/L) and 0.183% (6.00 mmol/L), respectively. Conclusion The tissue engineered epidermis constructed on polycarbonate membrane has normal composition and structure and barrier function corresponding to the normal epidermis.