Biomedical subjects

Wei-ren Dong

Publications and source records attributed to Wei-ren Dong.

5 recordsLinked to original sources

PubMed2006

Preparation and bioactivity of human hair keratin-collagen sponge, a new type of dermal analogue.

OBJECTIVE: To develop a three-dimensional porous film of human hair keratin (HHK)-collagen sponge complex for use as a dermal substitute. METHODS: The three components F, B, and Z derived from healthy human hair were weaved into a meshwork and integrated with purified soluble type I collagen extracted from bovine tendons to prepare a highly porous film with vacuum freeze-drying followed by secondary cross-linking with glutaraldehyde. The film was grafted beneath the dorsal skin in 21 SD rats (experimental group), with simple collagen sponge serving as the negative control. The rats receiving surgical operation but without graft served as the blank control. The graft and its surrounding tissue were harvested on days 3, 7 and at weeks 2, 4, 6, 8, 12 after implantation for evaluation of tissue compatibility, vascularization and degradation. RESULTS: The prepared collagen sponge film was semitransparent and porous. Three to 7 days after grafting, inflammatory reaction was relieved gradually, and several fibroblasts and blood vessels were found adherent to the grafts in the experimental groups. At week 4, the wounds healed in the experimental groups, and the fibroblasts were actively secreting collagen and the film degraded obviously with the appearance of elastic fibers. At weeks 6 and 8, new collagen fibers thickened and assumed regular arrangement, and the collagen sponge films disappeared completely. In the control groups, the changes were less obvious and total HHK degradation occurred till week 12. CONCLUSION: The degradable and absorbable HHK-collagen sponge film has relatively satisfactory tissue compatibility and can accelerate wound healing by stimulating cell proliferation and vascularization, showing the potential as an optimal dermal substitute.

Animals↗

PubMed2006

Ooplasmic transfer: problems and prospects.

Cytoplasmic transfer between human oocytes, which represents a complete cytoplasmic exchange, has been performed recently as a means to improve the outcome of assisted reproduction and becomes a hotspot of researches. Many studies have indicated that mitochondria in the oocytoplasm obviously affect fertilization of the oocytes and early embryo development. However, ooplasmic transfer can lead to mitochondrial DNA heteroplasmy and the prospect of mitochondrial heteroplasmy and its potential problems necessitate further studies. The authors reviews the ooplasmic transfer, the relation between ooplasm and fertilization and embryo development, and the mitochondrial heteroplasmy. The authors also propose a new theory of "reverse cloning technique".

Cytoplasm↗

PubMed2004

[In vivo tissue engineering: a new concept].

From our over a decade-long experience in experiments and clinical applications of human hair keratin (HHK) artificial tendon, a conclusion was drawn that HHK artificial tendon components and their degradation products could stimulate the proliferation and differentiation of tenoblasts in the neighboring tissues into tenocytes. With the regulation of this process by certain cytokines secreted by other cells, autotendons can be finally formed. We also found that after grafting for the tissue defects such as in the bone, nerve and muscle, "in situ construction" of the tissue/organ substitutes occurred, which inspired us to propose a wholly new theoretical system--in vivo tissue engineering, defined as in vivo reconstruction of the defected tissues or organs. The grafted absorbable scaffold biomaterial itself and its degradation products can activate the mitosis, proliferation, and differentiation of adult stem cells in the surrounding tissues, which organically interact with the material to form an organic complex under in vivo physiological conditions. Finally the matrix material is completely replaced by the complex, an almost identical structure with the normal tissue in terms of anatomy and histology. One of the advantages of in vivo tissue engineering is "in vivo construction" of the tissue/organ substitutes in anatomy, histology and function way of "in vivo cultivation" of the seed cells under in vivo microenvironment and in vivo precise regulation mechanism. It solves such problems as immune rejection against seed cells, variation and functional deterioration of the seed cells, complicated preservation procedure, transportation and high cost. The most prominent advantage of this technique is that it best meets the clinical need, not only in the sense of its powerful clinical potential, but also in its significant theoretical value.

Artificial Organs↗

PubMed2004

[Effect of insulin on expression of whole-blood platelet membrane P-selectin].

OBJECTIVE: To investigate the effects of insulin on the expression of whole-blood platelet membrane P-selectin. METHODS: Flow cytometry (FCM) was used to detect the expression of whole-blood platelet membrane P-selectin, and the effect of insulin on the expression on quiescent and activated plasma platelet observed in normal young subjects. RESULTS: Insulin had no effect on the P-selectin expression on quiescent platelet membrane, but significantly inhibited the up-regulation of P-selectin expression induced by thrombin and collagen respectively, exhibiting dose- and time-dependent effects. CONCLUSION: Insulin can inhibit P-selectin expression on activated platelet membrane.

Adolescent↗

PubMed2003

[Effect of insulin on the expression of platelet membrane glycoprotein II b/III a and its mechanisms].

OBJECTIVE: To investigate the effects of insulin on the expression of platelet membrane glycoprotein (GP) IIb/III a and its mechanism in normal subjects. METHODS: Flow cytometry was used to detect the expression of the whole-blood platelet membrane GP b/ a. The respective effects of insulin, L-nitro-arginine methyl ester (L-NAME) and methylene blue (MB) and their combination on the expression of GP b/ a were also studied. RESULTS: Insulin had no effect on the expression of GP II b/III a in healthy subjects, but significantly inhibited the up-regulated expression of GP II b/III a induced respectively by thrombin and collagen. The inhibitory effects of insulin on thrombin- or collagen-induced expression of platelet membrane GP II b/III a were dose- and time-dependent, and could be completely blocked by L-NAME or methylene blue. CONCLUSION: Insulin may inhibit the over-expression of platelet membrane GP IIb/III a by NOS-->NO-->GC-->GMP pathway.

Adolescent↗