BACKGROUNDCervical keratinocytes are recovered at a low numbers and frequently associated with contaminating human fibroblasts which rapidly overgrow the epithelial cells in culture with medium supplemented with 10% fetal bovine serum (FBS). However, it is difficult to initiate keratinocyte cultures with serum-free keratinocyte growth medium alone because cell attachment can be poor. Therefore, the culture of these cells is extremely difficult. In this study, we described a modified culture medium and coated culture plastics for growing normal human cervical epithelial cells in vitro.

METHODSNormal cervical epithelial tissue pieces were obtained and digested with type I collagenase to dissociate the cells and a single cell suspension produced. The cells were cultured on plastic tissue culture substrate alone or substrate coated with collagen type I from rat tail, with modified keratinocyte serum-free medium (K-SFM) supplemented with 5% FBS. After attachment, the medium were replaced with K-SFM without FBS. The expression of basal keratins of the ectocervical epithelium, K5, K14 and K19 were assayed by immunofluorescence with monoclonal antibodies to identify the cell purity.

RESULTSOur results indicate that cells attached to the culture plastic more quickly in K-SFM supplemented with 5% FBS than in K-SFM alone, as well as to tissue culture plastic coated with collagen type I than plastic alone. The modified medium composed of K-SFM and 5% FBS combined with a specific tissue culture plastic coated with collagen type I from rat tail was the best method for culture of normal cervical epithelial cells. K5, K14 and K19 were assayed and keratinocyte purity was nearly 100%.

CONCLUSIONA novel, simple and effective method can be used to rapidly obtain highly purified keratinocytes from normal human cervical epithelium.

Cell Culture Techniques ; methods ; Cervix Uteri ; cytology ; Epithelial Cells ; cytology ; Female ; Humans ; Keratinocytes ; cytology

Scar, either hypertrophic scar or keloid, is one of the most common complications due to proliferative disorder of fibrosis in the process of wound healing after burn injuries, trauma, and surgical operations. To repair the cosmetic and functional impairments caused by scars poses a great challenge to all the burn surgery workers. With the advances in both basic research and clinical treatment, the understanding of scar formation and the therapeutic strategies of scar have been improved significantly. However, the remaining problems are still outstanding. In this discussion, the advances and problems in the scientific research in this field, including genetic predisposition, candidate gene, dysfunction of fibroblasts, interaction between fibroblasts and keratinocytes, as well as animal models for hypertrophic scar and keloid were summarized. In addition, the progresses in the clinical therapies are also discussed, including pressure treatment, silicone gel sheeting, corticosteroids, laser, and other emerging treatment strategies. The understanding and treatment of scar will improve in the future with further deepening basic research and clinical trials with stricter standard of assessment.
Burns ; pathology ; Cicatrix ; genetics ; pathology ; therapy ; Fibroblasts ; cytology ; Humans ; Keratinocytes ; cytology

OBJECTIVETo construct an in vitro equivalent of the pigmented skin using tissue engineering methods.

METHODSSurgically removed foreskins was used as the source of keratinocytes and melanocytes harvested by routine tissue digestion. The fibroblasts were enriched by tissue block culture and seeded into the scaffold constructed using mouse tail collagens to construct the pigmented skin equivalent model. The general structure and the melanocyte distribution and growth status in this model were observed with HE staining and Fontana Masson staining. The ultrastructure of the constructed pigmented skin equivalent was observed by transmission electron microscope.

RESULTS AND CONCLUSIONThe pigmented skin equivalent model was structurally intact, and allowed optimal cell growth. Fontana Masson staining identified in the basal layer numerous melanocytes in normal growth, and the constructed model was structurally similar to normal skin tissue, suggesting successful construction of the pigmented skin equivalent model.

Animals ; Foreskin ; cytology ; Humans ; Keratinocytes ; cytology ; Male ; Melanocytes ; cytology ; Mice ; Skin Pigmentation ; Skin, Artificial ; Tissue Engineering ; methods

The efficiency and safe range of Lipofectamine2000 (LF2000)/bcl-xl applied in human keratocytes, the optimal ratio of LF2000/bcl-xl and the bcl-xl gene expression in human keratocytes were investiaged. By using trypan-blue staining, the effects of LF2000 and bcl-xl on the survival rate of the cultured human keratocytes were measured respectively. By using semi-quantitative RT-PCR, the efficiency and the expression of LF2000-mediated bcl-xl transfection into keratocytes were examined. The results showed that the survival rate of human keratocytes had no signficant change in the presence of LF2000 (20 microg/ml) or bcl-xl (10 microg/ml) for 24 h. LF2000 could effectively mediate the transfection of exogenous gene bcl-xl into human keratocytes. The best transfection efficiency could be obtained when the ratio of bcl-xl/LF2000 was 1:8. One day after transfection, the positive cells for bcl-xl could be detectable, and the positive rate reached the peak-on the posttransfection day 3 (48.3%), then gradually decreased. Fifteen days after transfection, there were few positive cells. It was suggested that LF2000 could effectively transfer the exogenous gene bcl-xl into human keratocytes without obvious toxicity during a concentration range. LF2000/bcl-xl may be likely to play an important role in gene therapy of human keratocytes.
Cations/administration & dosage ; Cornea/cytology ; Gene Therapy ; Keratinocytes/cytology ; Keratinocytes/*metabolism ; Liposomes ; Transfection ; bcl-X Protein/biosynthesis ; bcl-X Protein/*genetics

OBJECTIVETo construct a tissue-engineered skin flap using composite skin and adipose tissue constructed by adipose-derived stem cells(ASCs).

METHODSHuman ASCs isolated from adipose tissue were cultured and identified for their adipogenic, osteogenic and chondrogenic differentiation potentials. ASCs were then mixed with collagen gel for adipogenic induction and observed 15 days later with inverted microscope, oil-red O staining and HE staining. To construct the composite skin, keratinocytes and fibroblasts were isolated from human foreskin. The fibroblasts were mixed with collagen gel and cultured for 5 days, and keratinocytes were seeded on the gel for 4 days before transfer of the culture to air-liquid interface for culture for another 10 days. The adipose tissue and composite skin were then assembled according to the structure of normal skin and cultured for 3 days with HE staining observation.

RESULTSThe cultured ASCs were capable of adipogenic, osteogenic and chondrogenic differentiation, and adipogenic induction of the ASCs-gel complex for 15 days resulted in adipogenic differentiation of the ASCs in gel. The assembled tissue-engineered skin consisted of 3 layers, including a suprabasal layer formed by the stratified and differentiated keratinocytes, the middle layer and sublayer containing numerous cells, and a underlying sublayer formed by the adipogenic ASCs.

CONCLUSIONTissue-engineered skin flap can be constructed by assembling composite skin and adipose derived from cultured keratinocytes, fibroblasts, and ASCs.

Adipocytes ; cytology ; Adipose Tissue ; cytology ; Cell Culture Techniques ; Cells, Cultured ; Fibroblasts ; cytology ; Humans ; Keratinocytes ; cytology ; Stem Cells ; cytology ; Surgical Flaps ; Tissue Engineering

OBJECTIVETo reproduce a model of heat injured KC in vitro and explore its apoptosis rate of KC due to heat injury at different temperature.

METHODSHuman KCs were cultured in vitro, and they were incubated at 37, 41, 43, 45, 48, and 51 degrees C respectively for 10 mins in water bath. Trypan blue staining and Hoechst 33258 fluorescence staining were used respectively to determine necrosis and apoptosis of KC. Rates of apoptosis and necrosis of KC were analyzed quantitatively by flow cytometer. The proliferation activity of KC after heat injury was detected by MTT test.

RESULTSThe results of trypan blue staining, Hoechst 33258 fluorescence staining, and flow cytometer demonstrated that number of apoptotic and necrotic KC increased gradually along with a rise of water bath temperature. The rates of apoptosis and necrosis of KC were respectively (12.3 +/- 3.2)% and (14.1 +/- 1.6)% at 45 degrees C, (27.7 +/- 5.1)% and (58.0 +/- 4.2)% at 48 degrees C. Rate of KC necrosis reached up to (83.0 +/- 5.3)% at 51 degrees C. Inhibition of KC growth reached a stationary phase when the injurious temperature reached 45 degrees C as observed with MTT test.

CONCLUSIONSHeat injury can induce apoptosis and growth inhibition of KC in vitro. Incubating KC at 45 degrees C for 10 mins is a good condition to reproduce a model of heat injured KC in vitro. This model may be used to study the biological character and apoptosis of KC after burn injury.

Apoptosis ; Burns ; Cell Proliferation ; Cell Survival ; Cells, Cultured ; Flow Cytometry ; Hot Temperature ; Humans ; Keratinocytes ; cytology

BACKGROUNDTrichophyton rubrum represents the most common infectious fungus responsible for dermatophytosis in human, but the mechanism involved is still not completely understood. An appropriate model constructed to simulate host infection is the prerequisite to study the pathogenesis of dermatophytosis caused by T. rubrum. In this study, we intended to develop a new T. rubrum infection model in vitro, using the three-dimensional reconstructed epidermis - EpiSkin ®, and to pave the way for further investigation of the mechanisms involved in T. rubrum infection.

METHODSThe reconstructed human epidermis (RHE) was infected by inoculating low-dose (400 conidia) and high-dose (4000 conidia) T. rubrum conidia to optimize the infection dose. During the various periods after infection, the samples were processed for pathological examination and scanning electron microscopy (SEM) observation.

RESULTSThe histological analysis of RHE revealed a fully differentiated epidermis with a functional stratum corneum, which was analogous to the normal human epidermis. The results of hematoxylin and eosin staining and the periodic acid-Schiff staining showed that the infection dose of 400 conidia was in accord with the pathological characteristics of host dermatophytosis caused by T. rubrum. SEM observations further exhibited the process of T. rubrum infection in an intuitionistic way.

CONCLUSIONSWe established the T. rubrum infection model on RHE in vitro successfully. It is a promising model for further investigation of the mechanisms involved in T. rubrum infection.

Animals ; Disease Models, Animal ; Epidermis ; microbiology ; Humans ; Keratinocytes ; cytology ; Tissue Culture Techniques ; Trichophyton ; pathogenicity

Wound healing is a complex regeneration process, which is affected by lots of endogenous and exogenous factors. Researches have confirmed that acid environment could prevent wound infection and accelerate wound healing by inhibiting bacteria proliferation, promoting oxygen release, affecting keratinocyte proliferation and migration, etc. In this article, we review the literature to identify the potential relationship between the pH value of wound micro-environment and the progress of wound healing, and summarize the clinical application of variation of pH value of micro-environment in wound healing, thereby to provide new treatment strategy for wound healing.
Cell Proliferation ; Humans ; Hydrogen-Ion Concentration ; Keratinocytes ; cytology ; Wound Healing ; Wound Infection ; prevention & control

OBJECTIVETo investigate the migrating effect of adipose derived stem cells (ADSCs) on the wound model of human epidermal keratinocyte (HEKa).

METHODSRat ADSCs (rADSCs) were isolated and cultured (n = 10), rADSCs were direct co-cultured with HEKa cells in experiment group (experimental group, n = 10). In the control groups, rADSCs were indirect co-cultured with HEKa cells in transwell chamber (indirect group, n = 8), or HEKa was cultured alone (single group, n = 8). Then confluent HEKa cells were scraped to establish a wound model under invert microscope. After scraped 24, 48, and 72 h, cell numbers of which migrated across the edge of the wound was measured, the rate of wound healing was calculated by using SigmaScan Pro 5 software, and the proliferating effect of rADSCs on HEKa were examined by incorporation of [(3)H] thymidine.

RESULTSThe cells migrated across the edge of wound after 24 hours in experimental group, indirect group, and single group were (9.2 + or - 0.2), (5.0 + or - 0.3), (4.2 + or - 0.3), and were (58.5 + or - 0.4), (26.5 + or - 0.3), (20.7 + or - 0.5) 48 hours after, and were (125.8 + or - 0.4), (43.0 + or - 0.5), (35.6 + or - 0.5) cells/HP 72 hours after, respectively; the numbers were all significantly higher in experimental group than those in control groups (P < 0.05). The rates of wound healing after scraped 72 hours were 61.0% + or - 3.0%, 35.0% + or - 2.5% and 32.0 + or - 2.1%, the outcome in experimental group was significantly better than in the control groups (P < 0.05). And the thymidine feeding displayed the proliferation of HEKa in the three groups were (1440 + or - 210), (1050 + or - 280) and (1130 + or - 390) cpm/10(5) cell, and there was significant difference between the experimental and the control groups (P < 0.05).

CONCLUSIONSThe rADSCs can promote the migration of HEKa by direct contact with it.

Adipose Tissue ; cytology ; Animals ; Cell Count ; Cell Proliferation ; Cells, Cultured ; Coculture Techniques ; Epidermis ; cytology ; Humans ; Keratinocytes ; cytology ; Rats ; Rats, Sprague-Dawley ; Stem Cells ; cytology ; Wound Healing

OBJECTIVETo establish the tridimensional culture method for tissue-engineered skin to observe the histomorphological change in human immortal KC strain (HacaT)cocultured with xenogenic acellular dermal matrix (ADM).

METHODSThe ADM was prepared from SD rats by a modified method. HaCaTs were cultured in defined KC-serum free medium. HaCaTs in log growth phase were inoculated on ADM at the cell density of 2 x 10(5)/cm(2). They were submergedly cultured for 5 days and then changed to air-liquid phase culture for another 5 days. ADM and growth of HaCaTs on day 1 and 5 after cocultured with ADM were observed with scanning electron microscope. The histological change in ADM and HaCaTs on day 1, 5, and 10 after cocultured with ADM were examined by HE staining.

RESULTSThe gross appearance of ADM was white with smooth and soft texture, and intact collagen bundles without cellular residue. HaCaTs adhered and stretched out pseudopodia on the surface of the ADM on day 1 after combined culture, and a monolayer of cells was formed on day 5, growing into 3-6 layers of cells on day 10 with a tendency to grow into ADM.

CONCLUSIONSSD rats ADM is benefit for the adhesion of HaCaTs and the permeation of nutrient solution, from which an engineered multiple-layered human skin can be obtained within 10 days.

Animals ; Cells, Cultured ; Coculture Techniques ; Dermis ; cytology ; Humans ; Keratinocytes ; cytology ; Rats ; Rats, Sprague-Dawley ; Skin, Artificial ; Tissue Engineering ; methods