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Biomedical subjects

Yi-lin Cao

Publications and source records attributed to Yi-lin Cao.

At least 19 recordsLinked to original sources
PubMed2006

[Clinical study on keloid treatment with intralesional injection of low concentration 5-fluorouracil].

OBJECTIVE: To explore the effect of intralesional injection of low concentration 5-fluorouracil (5-FU) on inhibition of angiogenesis of keloid. METHODS: 35 patients with 51 keloids were treated with intralesional injection of 5-FU (2-5 mg/ml) biweekly. After 3-6 times of injection, the keloids were treated with intralesional injection of corticosteroid. The average period of treatment was 10.29 months. RESULTS: The efficacy of inhibiting keloid angiogenesis by low concentration of 5-fluorouracil was 96.77%. For the patients who were treated over 6 months with both 5-FU and corticosteroid, the total efficacy was 97.14%. Among them, 45.71% of keloids achieved complete remission, 48.57% mostly remission, 2.86% partial remission and 2.86% no remission. CONCLUSION: Inhibition of keloid angiogenesis with intralesional injection of low concentration of 5-fluorouracil along with corticosteroid injection can achieve satisfactory result.

Adrenal Cortex Hormones↗
PubMed2006

[Effect of adeno-BMP7 transfection on osteogenesis of BMSCs].

OBJECTIVE: To study the effect of adeno-BMP7 transfection on the biology of bone marrow stromal cells (BMSCs). METHODS: Bone marrow was obtained from the goat. The BMSCs were isolated and cultured at the second passage. Once the cells attached and formed a monolayer with 70%-80% confluency, adeno-BMP7 (M.O.I. = 100) was added to the cells. After three days, calcium node was examined with staining; cell-coral compound was replanted subcutaneously. RESULTS: With adeno-BMP7 transfection, BMP7 expression was detected with Western-blot; big calcium nodes were observed with staining. New bone formation was enhanced, which was evaluated by X-ray and histological examinations. CONCLUSIONS: BMSCs transfected with adeno-BMP7 show much stronger osteogenic ability.

Adenoviridae↗
PubMed2006

[Repair of canine segmental mandibular defects using autogenous bone marrow stromal cells and coralline hydroxyapatite].

OBJECTIVE: To repair segmental mandibular defects with autogenous bone marrow stromal cells (BMSCs) and coralline hydroxyapatite. METHODS: Isolated BMSCs were in vitro expanded and osteogenically induced. In 11 canines, a 3 cm segmental mandibular defect in right mandible was created. Five canine's defects were repaired with cell-scaffold constructs made from induced BMSCs and coralline hydroxyapatite (CHA); Others were repaired with CHA as control. The engineered bone was evaluated by X-ray, CT, gross and histological examination, biomechanical test 12, 26, 32 weeks post-operation respectively. RESULTS: BMSCs grew well on the CHA. X-ray and CT images showed better callus formation at connection sites in experimental group over time while worse formation at connection sites eventually in control group. At 32 weeks post-operation in experimental group, the defects were well repaired grossly. Histologically, there were bony healing and lamellar bone formation, in experimental group fibrous healing and woven bone formation in control group. Biomechanical test revealed no significant difference between experimental group and normal control group. CONCLUSIONS: Canine segmental mandibular defects can be ultimately repaired with the tissue-engineered bone generated by autogenous osteogenic BMSCs and CHA scaffold.

Animals↗
PubMed2005

[Cartilage-derived morphogenetic protein 1 initiates chondrogenic differentiation of human dermal fibroblasts in vitro].

OBJECTIVE: To explore the factors influencing the differentiation of fibroblasts into chondrocyte phenotype induced by a growth factor, cartilage-derived morphogenetic protein 1 (CDMP1). METHODS: Fibroblasts isolated from foreskin obtained during circumcision were cultured in the forms of micromass and monolayer culture. The culture fluid of the fibroblasts at the passage 2, 7, and 10 was added with CDMP1 of the concentrations at the concentrations of 10, 30, 100, and 300 ng/ml respectively and co-cultured for 7 days. RT-PCR was used to detect the expression of bone morphogenetic protein receptor (BMPR), activin receptor-like kinase (ALK) receptor, collagen types II, IV, and X before and after CDMP1 induction. Western blotting was used to detect the protein expression of collagen types II, a transcriptional factor Sox9, and aggrcan before and after the induction. Flow cytometry was used to detect the superficial markers CD29, CD105, CD106, and CD166, and the expression of collagen types I and II. RESULTS: Western blotting showed that the collagen type II positive cell rate in the passage 5 cells was 74.3% +/- 0.4%, not significantly different from that of the passage 2 cells (73.4% + 0.5%). When the concentrations of CDMP1 were 10 and 30 ng/ml no expression of aggrecan and collagen type II was detected, When the concentrations of CDMP1 was 100 and 300 ng/ml, the expression of aggrecan and collagen type II could be detected and without significant differences between these 2 concentrations. The expression of aggrcan and collagen type II mRNA disappeared in the monolayer cultured P2 and P5 fibroblasts induced by CDMP1 for 14 days, However, RT-PCR and Western blotting showed expression of collagen type II, aggrcan and SOX9 in the micromass cultured fibroblasts. RT-PCR showed that all fibroblasts cultured in vitro expressed ActR-I/ALK-2, BMPR-IA/ALK-3, and BMPR-IB/ALK-6 genes, and the expression of these genes significantly increased after CDMP1 for 7 days. CONCLUSION: CDMP1 stimulates the human dermal fibroblasts expanded in vitro to differentiate into chondrogenic phenotype in a dose dependent manner. Three-dimensional culture environments accelerate the chondrogenic differentiation. The expression of ALK receptors may involve the CDMP1 stimulated differentiation of fibroblasts.

Adolescent↗
PubMed2005

[Human adipose derived stem cells suppress lymphocyte proliferation induced by cellular or nonspecific mitogenic stimuli].

OBJECTIVE: To study immunological properties of adipose derived stem cells (ADSC) and their in vitro immunomodulatory effects on lymphocytes. METHODS: ADSC was isolated from fat tissue by liposuction and culture expanded. Cells at passage 2 were observed for the expression of HLAI, HLAII by FACs analysis. Peripheral blood lymphocytes (PBL) were cultured with allogeneic ADSCs at dose of 1 x 10(5). A third-party ADSCs at dose of 1 x 10(2), 1 x 10(3), 1 x 10(4), 1 x 10(5) were added to the ongoing two-way mixed lymphocyte reactions (MLR) for 6 days. Value of CPM (count per minute) was calculated with luminescence counter. RESULTS: Flow cytometry showed that undifferentiated ADSCs express HLA class I but not class II. Addition of interferon gamma (IFN-gamma) for 48 hours induced greater than 90% of cells to express HLA class II. No lymphocyte response was induced by allogeneic ADSCs as stimulators. Results were similar using ADSCs pretreated with IFN-gamma. ADSCs elicited inhibit function of mixed lymphocyte cultures in a dose dependent way. Even if ADSCs were pretreated with IFN-gamma, the suppression ability was maintained. CONCLUSION: Undifferentiated ADSCs do not elicit alloreactive lymphocyte proliferative responses and could modulate immune responses in vitro.

Adipocytes↗
PubMed2005

[Ectopic osteogenic ability of BMSCs on various scaffold materials in nude mice].

PURPOSE: To explore the ectopic osteogenic abilities of bone marrow stromal cells (BMSCs) on different scaffold materials in nude mice. METHODS: Canine BMSCs in vitro cultured were seeded at the density of 1x10(6)cells/cm(2) onto scaffolds of freeze-dried demineralized bone matrix (fdDBM), tricalcium phosphate (TCP), 200microm coralline hydroxyapatite (CH200) and 500microm coralline hydroxyapatite (CH500). The cell adherence and growth on the materials were examined by SEM and H&E staining after 4 to 7 days of in vitro culturing. To observe the ectopic osteogenic capacity, four 10mmx5mmx2mm cell/scaffold complexes (fdDBM, TCP, CH200, CH500) and a blank control scaffold (fdDBM only) were implanted subcutaneously into each of athymic mice (n=8). The implants were harvested after 9 weeks and H&E stained. Newly formed trabecular bone volume (TBV) was measured by IMAGER-PRO PLUS software, and statistical analysis was performed by ANOVA with SAS software. RESULTS: Canine BMSCs adhered to all 4 types of scaffolds and spread well in their pores 7-8 days after seeding. Athymic subcutaneous ectopic osteogenesis were observed in all the specimens of TCP, CH200, CH500 but were observed only in 75% of BMSCs/fdDBM and 25% of fdDBM. The TCP group showed significant higher TBV percentage (28.2%+/-2.86) than CH200 group (24.1%+/-4.12) and CH500 group (18.1%+/-4.66) (P<0.01). CONCLUSIONS: BMSCs adhered to all 4 scaffolds. When combined with BMSCs, TCP exhibited the greatest osteogenic potential, which indicates that it might be an excellent scaffold material in the field of bone tissue engineering. Supported by National 973 Project (G1999054300) and National Natural Science Foundation of China(30271426).

Animals↗
PubMed2005

Use of autologous tissue engineered skin to treat porcine full-thickness skin defects.

OBJECTIVE: To explore a feasible method to repair full-thickness skin defects utilizing tissue engineered techniques. METHODS: The Changfeng hybrid swines were used and the skin specimens were cut from the posterior limb girdle region, from which the keratinocytes and fibroblasts were isolated and harvested by trypsin, EDTA, and type II collagenase. The cells were seeded in Petri dishes for primary culture. When the cells were in logarithmic growth phase, they were treated with trypsin to separate them from the floor of the tissue culture dishes. A biodegradable material, Pluronic F-127, was prefabricated and mixed with these cells, and then the cell-Pluronic compounds were seeded evenly into a polyglycolic acid (PGA). Then the constructs were replanted to the autologous animals to repair the full-thickness skin defects. Histology and immunohistochemistry of the neotissue were observed in 1, 2, 4, and 8 postoperative weeks. RESULTS: The cell-Pluronic F-127-PGA compounds repaired autologous full-thickness skin defects 1 week after implantation. Histologically, the tissue engineered skin was similar to the normal skin with stratified epidermis overlying a moderately thick collageneous dermis. Three of the structural proteins in the epidermal basement membrane zone, type IV collagen, laminin, and type VII collagen were detected using immunohistochemical methods. CONCLUSIONS: By studying the histology and immunohistochemistry of the neotissue, the bioengineered skin graft holds great promise for improving healing of the skin defects.

Animals↗
PubMed2005

[Stem cell, the basis for tissue and organ reconstruction].

Seed cells are prerequisite for reconstruction of artificial tissues/organs by tissue engineering approach. It has been widely accepted that stem cells are the best candidate for tissue engineering. The successful repair of tissue damages with adult stem cell mediated tissue engineering therapy in both animal models and patients has demonstrated the feasibility of using this technique for tissue/organ regeneration. Further studies in allogeneic adult stem cells and the establishment of universal embryonic stem cells will be critical for the industrialization of tissue engineering in future.

Adult Stem Cells↗
PubMed2004

[Influence of mechanical stress on chondrogenesis of in vitro cultured porcine bone marrow stem cells: a preliminary study].

OBJECTIVE: To evaluate the influence of mechanical stress on chondrogenesis of in vitro cultured porcine bone marrow stem cells (BMSC). METHODS: Porcine BMSC of passage 2 were seeded onto a cylinder-shaped PGA/PLA scaffold, 8mm in diameter and 3mm in thickness, at a density of 5 x 10(7)/cm(3). After the cell-scaffold constructs were cultured for one week, the primary medium, high-glucose DMEM medium with 10% fetal bovine serum (FBS), was replaced by chondrogenically inductive medium containing TGFbeta(1) (10 ng/ml), IGF-I (50 ng/ml), and dexamethasone (40 ng/ml) in addition to DMEM+10% FBS. The constructs were randomly divided into three groups according to the imposed stress: experimental group A in which a centrifugal stress was imposed at 100 g, 30 min, 2/d; experimental group B in which a rotative stress was imposed at 80 rpm, 8 h/d by a shaker; and control group in which the constructs were statically cultured. The gross view, histology, histochemistry, immunohistochemistry and glycosaminoglycan (GAG) content were evaluated after 4 and 8 weeks respectively. RESULTS: Four weeks later, the constructs in both experimental groups maintained their original sizes and shapes. Histology showed nodular lacuna-like structures, in company with GAG deposition and collagen synthesis. In addition, collagen type II was detected by immunohistochemistry. In the control group, however, the constructs shrunk to a little smaller size than those in the experimental groups, and histological staining showed a little amount of lacuna. Eight weeks later, the constructs in both experimental groups still maintained the original sizes and shapes with good elasticity. HE staining showed massive lacuna-like structures in most areas of the construct and extracellular matrix deposited evenly. Fibrous tissues were only observed in some areas. Safranin-O staining showed massive GAG formation and Masson staining showed much more collagen formation than those in the control group. Immunohistochemical staining of collagen type II showed strong positive expression. In the control group the constructs showed massive fibrous tissues, with a small amount of lacuna-like structures in the peripheral areas. GAG contents in the 2 experimental groups were 5.98 mg/g and 5.62 mg/g respectively, both significantly higher than that in the control group (4.73 mg/g) without a difference between the 2 experimental groups. CONCLUSION: Mechanical stress promotes chondrogenesis and cartilage maturation of BMSC in vitro.

Animals↗
PubMed2004

[Cartilage-derived morphogenetic protein 1 initiates chondrogenic differentiation of human dermal fibroblasts in vitro].

OBJECTIVE: To investigate the feasibility of human dermal fibroblasts in vitro differentiation into chondrogenic phenotype with induction of cartilage-derived morphogenetic protein (CDMP) growth factor. METHODS: Human dermal fibroblasts were isolated from foreskin and cultured in monolayer ex vivo. Dermal fibroblasts of passage2 was plated at density of 1 x 10(4) cells/cm(2) and induced with CDMP1 (100 ng/ml) in medium of F12 + 10% FBS. After 7 days of induction, morphology of cells was observed under phase-contrast microscopy and the length:width ratio of cells was calculated by Image Plus software analysis. Expression of type I, II, III collagen was detected by immunofluorescence and observed with confocal microscopy. The method of Western-Blot was applied to detect secretion of collagen type II. mRNA expression of chondrogenic related Sox9, Aggrecan as well as collagen type II, IX was detected by RT-PCR. The osteogenic related expression of collagen type X, Alkaline Phosphatase (AKP) was also detected by RT-PCR. Pellet cultured dermal fibroblasts at a density of 2 x 10(7) cells/ml was observed respectively for proteoglycan and collagen type II expression with Alcian blue and immunohistochemistry staining. RESULTS: With the induction of CDMP1, the morphology of cells changed from spindle fibroblastic appearance to that of typical chondrocyte-like polygon shape. By Image Plus software analysis, it was found that the length/width ratio changed significantly from 7.40 +/- 1.30 of preinduction to 1.40 +/- 0.15 of post-induction (P < 0.05). No significant difference was found between the postinduction and normal chondrocyte (1.29 +/- 0.24). By confocal microscope observation, expression of collagen type II was found intracellularly in CDMP1 treated fibroblasts. Western-Blot detection confirmed collagen type II expression by 7 days induction. RT-PCR gene expression analysis of characteristic chondrogenic related genes, such as Sox9, Aggrecan as well as collagen type II, IX, revealed induction of chondrocytic phenotype in monolayered culture upon stimulation with CDMP1 for 7 days. While osteogenic related gene expression of collagen type X, AKP was not detected by RT-PCR, which indicates that osteogenic differentiation was not initiated by CDMP1 in 7 days culture. Histological staining of proteoglycan with Alcian blue and immunohistochemical staining cartilage specific type II collagen revealed deposition of typical cartilage extracellular matrix deposition in pellet cultured fibroblasts. CONCLUSION: These results suggests human dermal derived fibroblast could be differentiated into chondrogenic phenotype with CDMP1 induction in vitro.

Adolescent↗
PubMed2004

[Preliminary study on in vitro tendon engineering using tenocytes and polyglycolic acids].

OBJECTIVE: To find out the feasibility of tendon engineering in vitro using expanded tenocytes and polyglycolic acids (PGA). METHODS: Tenocytes were isolated using tissue explant method and expanded in vitro. Tenocytes (20 x 10(6)) at the second passage were collected and then seeded onto PGA unwoven fibers to form a cell-scaffold construct in a shape of tendon. The constructs were cultured in DMEM with 20% FBS for 1 week. The cell-scaffold constructs were then cultured under constant tension generated by a U-shaped spring (n = 5), which served as experimental group, or cultured without tension (n = 4), which served as control group 1. PGA fibers alone were cultured (n = 3), which served as control group 2. Small fragments at the end of the constructs were harvested at 2, 4 and 6 weeks respectively for histological and immunohistochemistry (IHC) analysis. Six-week samples were also evaluated by transmission electron microscope (TEM) and mechanical test. RESULTS: No obvious difference was observed among the three groups at 2 weeks grossly and histologically as the constructs remained to be mainly undegraded PGA fibers. By 4 weeks, a neo-tendon was formed in the experimental group and control group 1 grossly, and histology and IHC revealed the formation of collagen fibers. In contrast, PGA fibers alone in control group 2 were mostly degraded. At 6 weeks, tendons of control group 1 were much thicker [(2.55 +/- 0.18) mm in diameter] than those of experimental group [(1.44 +/- 0.13) mm in diameter]. Periodical striae were observed in collagen fibers of experimental group and control group 1 by TEM. However, histology of tendons in experimental group revealed longitudinally aliened collagen fibers, which resembled the structure of normal tendon more closely than that of control group 1 tendons. Furthermore, the maximum tensile stress (N/mm(2)) of experimental group (1.107 +/- 0.327) was greater than that of control group 1 (0.294 +/- 0.138) (P < 0.05). CONCLUSION: It is possible to use an engineering to construct tendon tissue in vitro. Periodical strain generated by bioreactor may be the optimal mechanical stimulation, which is currently under investigation.

Animals↗
PubMed2004

[Experimental study on in vitro lamina propria engineering using oral fibroblast and polyglycolic acids].

PURPOSE: This study investigated the feasibility of lamina propria engineering in vitro using expanded oral fibroblast(OFC) and Polyglycolic Acids (PGA). METHODS: OFC were isolated by tissue explant method and expanded in vitro. OFC (20x10(6)) of 3rd passage were collected and then seeded onto PGA unwoven fibers to form a cell-scaffold. The constructs were cultured in DMEM +10% FBS. The cell-scaffold constructs were observed continuously by microscope. Small fragments were harvested at 1 week for electromicroscope, histological and RT-PCR analysis. RESULTS: At the sixth day, a neo-lamina propria was formed. HE and Masson stain revealed the formation of collagen fibers. RT-PCR revealed the new forming collagen was mainly type I collagen. CONCLUSION: lamina propria tissue is possible to engineer in vitro using oral fibroblast and polyglycolic acids. At this basis, we can construct bi-layer tissue engineering oral mucosa in the further research.

Fibroblasts↗
PubMed2004

[Research advances and applications of the methods to repair mandible defect].

Mandible defects can be caused by many diseases, most commonly occurring in cranio-maxillofacial regions. With the development of orthopaedics, biomaterial and cell biology in these years, great improvements have been acquired in repair of mandible defects. This paper systematically reviewed the relevant research advances and applications, and showed the applied prospect of bone tissue engineering in this field.

Bone Regeneration↗
PubMed2004

[In-vivo tracing of bone marrow stromal cell differentiating into chondrocytes by green fluorescent protein gene transfection].

AIM: To achieve highly efficient, stable and long-term expression of green fluorescent protein(GFP) reporter gene in bone marrow stromal cells(BMSCs) and to trace directly the distribution and differentiation of BMSCs in articular cartilage defects. METHODS: Recombinant RV-GFP expression vector was constructed and transfected into packaging cell PT67. After G418 screening and amplification, cell clones producing high level recombinant viruses were obtained and in-vitro expanded. The virus supernatant from infected PT67 cell culture was used to infect BMSCs directly. Autologous GFP-labeled BMSCs were seeded onto biodegradable polymer and implanted into porcine articular cartilage defects. 7 months later, the repaired tissue was evaluated by confocal microscope. RESULTS: The constructed recombinant expression vector RV-GFP was identified by restriction digestion. The transfection rates of PT67 cells reached 20%-50%, which reached 100% after G418 screening, bright green fluorescence could be seen under fluorescence microscope. BMSCs could be transfected successfully by the culture supernatant from infected PT67 cells and GFP was expressed efficiently in a long-term period. Confocal microscope revealed that GFP-labeled cells existed in many neocartilage lacunae after 7 months. CONCLUSIONS: The recombinant vector RV-GFP can provide a simple, sensitive and reliable tool to label BMSCs which can be used to study cytologic dynamic follow-up in-vivo. BMSCs can differentiate into chondrocytes and play an important role in repairing articular cartilage defects.

Animals↗
PubMed2004

[Metabolism of hyaluronic acid and extremity lymphedema].

OBJECTIVE: To investigate the possible influence of the impairment of lymph fluid on the metabolism of hyaluronic acid (HA) in the lymphedematous skin tissue. METHODS: Tissue fluid was collected in lymphedematous limbs and the contralateral healthy limbs of 39 patients and HA content was measured with radioimmunoassay. The protein contents were also measured. RESULTS: The HA contents in interstitial fluid of lymphedematous limb were significantly (8 fold) higher than that of normal limb. The protein concentration in the tissue fluid did not show significant differences between lymphedema and those with normal tissue. CONCLUSION: The result suggests blockage of regional draining lymphatics may impairs breakdown of HA and the stagnation of HA in the limb may exert a deleterious effect on the interstitium.

Extracellular Fluid↗
PubMed2004

[Regeneration of autologous tissue-engineered cartilage by using basic-fibroblast growth factor in vitro culture].

OBJECTIVE: To investigate the effect of the basic fibroblast growth factor (b-FGF) to regenerate an autologous tissue-engineered cartilage in vitro. METHODS: The Cells were harvested from the elastic auricular cartilage of swine,and were plated at the concentration of 1 x 10(4) cells/cm2 , studied in vitro at two different media enviroments: Group I contained Ham's F-12 with supplements and b-FGF, Group II contained Ham's F-12 only with supplements. The passage 2 cells (after 12.75 +/- 1.26 days) were harvested and mixed with 30% pluronic F-127/Ham's F-12 at the concentration of 50 x 10(6) cells/ml. It was injected subcutaneously at 0.5 ml per implant. The implants were harvested 8 weeks after the vivo culture and examined with the histological stains. RESULTS: The chondrocytes displayed morphologically similar to the fibroblasts in the media containing basic-FGF. The number of cell doublings (after 12.75 +/- 1.26 days) in vitro culture was as the following: Group I, 70; Group II, 5.4. Eight 8 weeks after the vivo autologous implantation, the average weight (g) and volume (cm3) in each group was as the following: Group I, 0.371 g/0.370 cm3 Group II, 0.179 g/0.173 cm3 (P < 0.01). With the b-FGF in vitro culture, the cells were expanded by 70 times after 2 weeks. Histologically, all of the engineered cartilage in the two groups were similar to the native elastic cartilage. CONCLUSION: These results indicate that the basic-FGF could be used positively to enhance the quality and quantity of the seeding cells for the generation of the well-engineered cartilage.

Animals↗
PubMed2004

[Reconstruction of rabbit corneal stroma using tissue engineering technique].

OBJECTIVE: Reconstruct corneal stroma by tissue engineering. METHODS: Primary corneal stromal cells were isolated from newborn rabbit cornea. When the cultured cells reaching confluence, the stromal cells were mixed with polyglycolic acid (PGA) to form a cell-scaffold construct. After 1 week in vitro culture, the constructs were implanted into mother rabbit corneal stroma. Parts of corneal stromal cells were transfected with GFP gene as mark of transplanted cells. Tissues were harvested at 8 weeks for transmission electron microscopy (TEM), histology and Western blot evaluation. In control, PGA alone was implanted into the other cornea. RESULTS: The engineered corneal stroma became transparent gradually over a period of 8 weeks. The histology of engineered stromal lamellar was relatively similar to that of natural one, no significant differences were found in the diameter of cornea collagen fiber [(29.4 +/- 4.7) nm] in experimental rabbits compared with control [(28.5 +/- 3.5) nm], Student's t-test: P = 0.1316 > 0.05. TEM demonstrated that collagen fibrils deposited in engineered stroma had a similar diameter compared to that of normal counterpart. In addition, Western blot showed the positive expression of type I collagen in the collagen fibrils. In contrast, no new stroma tissue was formed when PGA alone implanted. A green colored stroma was observed when engineered with GFP-labeled cells under fluorescence light microscope. CONCLUSION: The results demonstrate that nearly transparent corneal stroma can be obtained by the technique of cornea engineering.

Animals↗