Objective To investigate the current situation, problems of medicinal biotechnology in China, and to provide the relevant countermeasures for its development. Methods We surveyed the units which could carry out medicinal biotechnology projects in 30 provinces except Tibet, and compared the results with that in America.Results The questionnaire were returned from 25 provinces (83.4%), and there were 1 477 medicinal biotechnology projects carried out by 149 units in the past 10 years. These projects ranged from basic biotechnology to regenerative medicine and stem cell researches. The basic research projects constituted quite large percentage among all the projects. But the development levels in different areas were imbalanced, cross correlation with the development levels of economy. An echelon team of talents has been developed, most of them were trained in China. The invested capital differed considerably among units, in general the amounts were insufficient. Most invested capital came from the government. The number of patent application for projects based on independent-developed technology was small. This showed that project principals had a poor understanding of patents. More than half of units did not have a Bioethics Committee. From the search result for documents, the number of articles on stem research of China was close to that in America; and the number of articles on gene treatment and tissue engineering has already exceeded that of America. However, research on gene diagnosis of China was lagging far behind America. Conclusions An echelon team of talents has been developed, most of them are trained in China.We should give full play to the advantage of the distribution of qualified personal resources in developed economical areas so as to promote the applicability and popularity of medicinal biotechnology in less developed areas.Regarding to applicability and development, we should first develop applied technology to form the core competetiveness of basic research, technology development and application; we should also strengthen the training in ethics and regulation to establish a set of scientific assessment of medicinal biotechnology and management system.
Objective To isolate neural stem cells (NSCs) from rabbit retina and brain, and induce differentiation of those NSCs using different culture media. Methods Single-cell suspensions of retina and cerebral cortex were prepared from rabbit embryo, cultured in 5 types of different media to isolate the NSCs by continual passages. After 3 passages, NSCs were induced to differentiation in 2 types of different media for 8 to 10 days. NSCs and inducedretinal cells were examined by immunofluorescence and flow cytometry for the expression pattern of some specific antigens.Results Immunofluorescence showed that NSCs from retina and brain, cultured in serumfree media, both expressed Nestin partially. Flow cytometry showed that Nestin positive cells were significantly decreased while the Rhodopsin and Thy1.1 positive cells were increased after induction. Compared with the combined induction of alltrans retinoid acid (ATRA) and serum, 5%FBS (fetal bovine serum) led to higher expression of Rhodopsin（P＜0.01），but lower expression of Thy1.1（P=0.01）.Conclusion Serumfree media with N2, EGF, bFGF, LIF is the best for NSCs purification. Both induciton media can induce NSCs to differentiate.Retina NSCs have higher potentials to differentiate into retinal neuroepithelial cells than brain NSCs.
Purpose To investigate the development of embryonic stem cells (ESC)in the subretinal space． Methods ESC were cultivated in suspension for 4 days till they developed into cell aggregates,i.e.embryonic body(EB).ESC as well as EB combined with or without RA were respectively transplanted into vitreous cavity and subretina1 space in SD rats,and the subretinal transplanted eyes,transient ischemia-reperfusion injuries were made by ligating the ophthalmic artery for 40 seconds before the transplantation .The experimental eyes were enucleated for histological and immunohistochemical assays after 14～28 d. Results The EB was found to develope into photoreceptors induced by RA in the subretinal space under an ischemia-reperfusion condition，and EB transplantation without RA induction induced multiple differentiations in the subretinal space.The single injection of RA without EB induced hyperplasia of the neural retinal cells.ESC transplanted into vitreous cavity rapidly proliferated and developed into atypical hyperplastic mass. Conclusion EB derived from ESC can differentiate into photoreceptors induced by RA in the host subretinal space under an ischemia-reperfusion condition. (Chin J Ocul Fundus Dis，2000，16：213-284)
This paper describes the latest definition, connotation, content and working mode of orthopedic rehabilitation. It points out that the main contents of orthopedic rehabilitation should include the rehabilitation of patients with orthopedic diseases after surgery and non-surgical treatment. The research progress of stem cells, especially mesenchymal stem cells, in the treatment of osteoarthritis and lumbar intervertebral disc degeneration are reviewed. The latest progress of platelet-rich plasma in the treatment of injury of articular cartilage, ligament and tendon injuries are also reviewed.
Objective To observe whether transforming growth factor-beta;2（TGF-beta;2）could promote the differentiation of retinal stem cells in rats cultured in vitro. Methods The retinal stem cells were separated from the embryonic ratsprime; eyes under the dissecting microscope, cultured, and subcultured. The cells were identified by nestin and Chx-10 immunofluorescence. The sixth generation of cells were induced and differentiated, immunofluorescent stained with anti-glial fibrillary acidic protein，anti-opsin, anti-b-tubulin, and anti-protein kinase C, and identified the final cells. Results The cultured cells after induced by TGF-beta;2 differentiated to the mature cells. The results of immunofluorescence showed that the differentiated cells induced by TGF-beta;2 were more than which induced by the embryonic bovine blood serum. Conclusion TGF-beta;2 may induce the retinal stem cell differentiating into retinal cells. The inductive and differentiating effect of TGF-beta;2 is ber than which of the blood serum. (Chin J Ocul Fundus Dis, 2007, 23: 104-107)
Objective To investigate an important role of the stem cells in reconstructing the tissues and organs. Methods Based on our own researches and combined with the review of the literature at home andabroad, the latest development of the cell therapy with the stem cells and the application of the seed cells in the tissue engineering were analyzed. Results As the stem cells are the origin of the human tissues and organs and have a higher self-renewal ability and extensive characteristics of proliferation in vitro, their imbedding and multi-differential potentialities were illustrated. Both the embryonic stem cells and the adult stem cells had a wide prospect as ideal seed cells for reparation and reconstruction of the impaired human tissues and organs. Conclusion The stem cells can play animportant role in repairing and reconstructing the injured tissues and organs and they have a promising prospect in clinical application. The further research and wide application of the stems cells will significantly improve the therapeutic effects on the injured tissues and organs.
Stem cells have been regarded with promising application potential in tissue engineering and regenerative medicine due to their self-renewal and multidirectional differentiation abilities. However, their fate is relied on their local microenvironment, or niche. Recent studied have demonstrated that biophysical factors, defined as physical microenvironment in which stem cells located play a vital role in regulating stem cell committed differentiation. In vitro, synthetic physical microenvironments can be used to precisely control a variety of biophysical properties. On this basis, the effect of biophysical properties such as matrix stiffness, matrix topography and mechanical force on the committed differentiation of stem cells was further investigated. This paper summarizes the approach of mechanical models of artificial physical microenvironment and reviews the effects of different biophysical characteristics on stem cell differentiation, in order to provide reference for future research and development in related fields.
Objective To review the recent progress of the researches in the field of cartilage tissue engineering, and to discuss the challenges in construction of tissue engineered cartilage. Methods Literature related with cartilage tissue engineering was reviewed and analyzed. Results Some techniques have been appl ied in cl inical. As far as the seeding cells, induced pluripotent stem cells have attracted much more attention. Current strategies of scaffold designing are trying to imitate both component and structure of natural extracellular matrix. Cartilage regeneration through the autologous cell homing technique el iminate the transplantation of exotic cells and has become the hot topic. Conclusion Successful treatment of the damaged cartilage using tissue engineering method will depend on the advances of stem cell technology development, biomimetic scaffolds fabrication and proper appl ication of growth factors.
Objective To investigate the viability and the characters of proliferation and differentiation of retinal stem cells (RSCs) after cryopreservation and anabiosis. Methods The RSCs of a Long Evans rat with the embryonic age of 17 days were separated and cultured in vitro. The third-passage RSCs in the cryopreservation liquid consisted of 80% Dulbecco modified Eagle medium (DMEM)/F12，10% bovine serum albumin (BSA)，10% dimethylsulfoxide (DMSO)，and basic fibroblast growth factor (bFGF) (20 ng/ml), were stored in liquid nitrogen. After 1, 2, 4, 8, 12, and 16 weeks of freezing period, these cells were thawed. The livability of the cells was counted and the differentiation was induced while the proliferation and characters of differentiation were detected by immunofluorescence. Results The effects of different durations of cryopreservation on the livability of RSCs did not differs much (Pgt;0.05). These cells were reculturd well and presented specific marker of RSCs. In addition, they also could be induced and differentiated into several types of retinal cells. Conclusion Cryopreservation and anabiosis of RSCs does not affect the cellular intrinsic characters of proliferation and differentiation. (Chin J Ocul Fundus Dis, 2007, 23: 94-97)
Objective To investigate the feasibility of differentiation of invitro induced rat bone marrowderived mesenchymal stem cells（rMSCs） into retinal pigment epithelial （RPE） cells.Methods The rMSCs from BrwonNorway (BN) rats were isolated and cultured by adherent screening method. RPE cells lysate made by repeated freezethawing was put into the rMSCs culture system to identify whether the induced cells could express characteristic label cytokeratin（CK）and S-100 simultaneously or not.Results The growth rate of rMSCs induced by RPE cells lysate was slower and protuberant burr surrounded the fusiform cells. The results of immunoblotting and double immunofluorescence showed that partial induced cells expressed CK and S-100 simultaneously. The result of flow cytometry indicated that 14.1% induced cells expressed CK and S-100 simultaneously.Conclusion Induced by RPE cells lysate, rMSCs can differentiate into RPE cells.