Jornal de ciência e engenharia de tecidos

Considering importance of stem cell based therapies for wound healing, we have previously established protocols for successful differentiation of stem cells (isolated from placenta) into skin-like cells (keratinocytes and fibroblasts). In the current study we aim to evaluate the effect of pre-differentiated skin-like-cells on wound healing potential using an in vitro burn injury model. The amniotic epithelial cells (AECs) and umbilical cord mesenchymal stem cells (UCMSCs) obtained from amniotic membrane and umbilical cord tissue; respectively, were differentiated into skin-like cells (keratinocyte and fibroblasts respectively). In order to make an in vitro burn injury model, keratinocytes and fibroblasts were isolated from rats and insulted with high temperature (up to 50oC). The optimal temperature for burn injury models was determined using viability assay, cytotoxicity level, proliferation, and expression of pro-apoptotic. In order to assess effectiveness of pre-differentiated skin like cells, the keratinocyte- and fibroblasts-like cells were co-cultured with injured keratinocytes and injured fibroblasts, respectively. Results indicated that optimal temperature for the induction of heat injury for both keratinocytes and fibroblasts was 50oC. At this temperature both types of cells (keratinocytes and fibroblasts) showed modified morphology, drastic cellular injury, least viability, higher expression of pro-apoptotic markers and lower expression of proliferation genes. Co-culturing of pre-differentiated cells leads to an increase in viability and proliferation concurrent with decreased apoptosis. We have established successfully in vitro model of burn injury that might be helpful to evaluate the wound healing potential of cells. Further, predifferentiated skin-like cells are a potential source for the treatment of severe burn injuries.

A post mortem examination was performed on a 45 year old white male who died suddenly during a competitive athletic swimming event. There were few clinical events seen in the year before his death. Clinical workup was negative and lung scan showed a small coin lesion was attributed to focal bacterial/fungal infection. Antibiotic treatment appeared to clear this condition on another follow up scan and he was sent home with an inhaler. On gross post mortem examination the lungs revealed diffuse pulmonary congestion, focal hemorrhage and edema. Small focal white areas of calcified lesions were also seen. In addition, an enlarged heart with left ventricular hypertrophy and thickened interventricular septum were seen. There was moderate atherosclerosis midway down the left anterior descending branch of the coronary artery observed. Histologic examination of lung tissue proved confirmatory for diffuse pulmonary ossification. Heart microscopic examination was consistent with cardiomyocyte hypertrophy. In conclusion, the diffuse pulmonary ossification was probably related to the sudden death with concomitant myocardial hypertrophy.

In the present work, chitosan/glycerol blends were used to prepare biodegradable films with potential application in dermal treatment. While the presence of glycerol gives the hydrating effect, the chitosan characteristics contribute to dermal regeneration. Swelling degree measurements, water vapor permeability determinations, mechanical tests, scanning electronic microscopy and Fourier transform infrared spectroscopy analysis; biodegradability studies, thermogravimetric and differential scanning calorimetry analysis were used to analyze the influence of the incorporation of significant amounts of glycerol in film properties. The obtained results suggested that the glycerol addition provide the films with the required properties for the intended application related to dermal treatment. Increasing the glycerol concentration, a cluster effect produced by the glycerol molecules surrounding the macromolecular chains led to a decrease in the swelling degree and an increase in the WVP along with improvements in mechanical properties.

Diabetic non-healing Ulcers are very difficult to treat. Many of such Patients undergo Amputations to lessen the morbidity. There is no defined management for them. Current management requires multiple surgical interventions, drugs and intense local dressing and care. The authors have developed an innovative therapy called as STARS (Sandeep’s technique for assisted regeneration of skin) for wound management. It is basically based on principle of regenerative medicine with autologous platelet rich Plasma (PRP) being the source of regenerative growth factors leading to complete healing of wounds. This case is a young female, a Juvenile Diabetic with non-healing infected ulcers on both heels since 3 years. She received STARS therapy and her one ulcer healed completely and second ulcer healed 40%. A complete healing of non healing diabetic ulcer without surgery, drugs and intense dressing, in an uncontrolled diabetic patient, is a milestone in such wound management. STARS therapy led by Platelet regeneration, is an innovative protocol for such cases.

A 60 year old woman was enrolled in our study. She was 151 cm tall, weighed 73 kg and had high body mass index (33.19 kg/m2). Adipose tissue specimens were taken from her abdomen by surgical excision. ASCs were isolated in primary culture and cell counts were performed by using an automated cell counter (LUNA™). And 5 × 103 ASCs were seeded into DMEM tissue culture flasks and were cultured for 16 days (n=3). Lastly, self-renewal capacity was demonstrated by colony-forming unit fibroblast (CFUF) assays (n=3).

Apical periodontitis is a relatively frequently encountered disease in clinical dentistry; however, its pathogenesis and etiology are not easily elucidated. Therefore, it is not always cured, even when carefully following the highest standards of treatment and intractable apical periodontitis may occur. In addition, in long-term root canal treatment of difficult cases with intractable pain, there may be misunderstandings between the dentist and patient. While acute pain is an indispensable symptom in detecting lesions and disease, sustained chronic pain can decrease an individual’s quality of life with various negative outcomes, including decreased motivation to work. Therefore, endodontic treatments and pain control measures for a diseased tooth in intractable apical periodontitis must be developed. This review outlines the progression from the onset of the lesion and examines the immunology of apical periodontitis based on studies of model animals, indicating that interleukin-1β is a key factor in elucidating the disease state and is expected to lead to the development of an effective treatment for refractory cases.

Background: Liver fibrosis is a reaction to chronic liver injury characterized by excessive accumulation of collagen. Due to their importance as biomarkers, the changes in gene expression in the liver during the development of fibrosis and its subsequent outcomes of cirrhosis, neoplasia or resolution are intensely studied. Quantitative realtime PCR (qPCR) with its ability to detect and measure minute amounts of nucleic acids have been increasingly used in these studies. In qPCR, the quantitation of mRNA is relative and the accuracy of results dependent on the reference genes used for standardization. However, many genes studied are normalized against single reference genes, usually housekeeping genes, without adequate justification.
Methods: For the dimethylnitrosamine (DMN) induced liver fibrosis rat model, we tested 8 commonly used candidate genes (Actb, Alb, Sdha, B2m, Rn18s, Hprt1, Ppia and Gapdh) to determine their suitability as reference genes. qPCR results were analysed using four commonly used programs; NormFinder, GeNorm, Comparative ΔCt methods and BestKeeper.
Result: It was determined that Gapdh and B2m were the most stable genes in normal liver. However, in DMN treated livers, Gapdh and Ppia were the most stably expressed reference genes. We validated these reference genes by using them to normalize the expression of four genes; Tgfb 1, Col1a1, Col3a1 and Tnf known to be highly expressed in liver fibrosis.
Conclusion: Gapdh and Ppia are the most suitable reference genes for the normalization of qPCR data in gene expression studies of the liver in the DMN induced liver fibrosis model in the rat. We advise against the use of Actb in this experimental setting because of its low expression stability.

Regeneration of neural injuries by formation of new axons and myelination to improve quality of patient life is undeniable difficulty in the world in which scientists examined different strategies from ancient times. Recently, 3D tissue engineering scaffolds simulated original extracellular matrix (ECM) and provide desirable substrate for cellular attachment, proliferation and differentiation. However, similarity of scaffold’s materials to ECM contaminant is effective in achieving better results. Investigations demonstrated that oriented fibers, pores and unidirectional channels or conduits act as cell guidance and showed significant effect on cellular differentiation and axonal reconstruction. Between all the methods of scaffold fabrication, freeze casting provides lamellar type and controlled pores that are necessary in neural tissue engineering. In brief, designing scaffolds with oriented structure such as freeze casting with unidirectional solidification and seeding an appropriate cell before implantation improve repair process of neural damages.

A key challenge in glioblastoma biology and relevant tumor environment modeling lies in understanding of the cellular interactions occuring within the context of a 3-dimensional (3-D) human tissue microenvironment. Recently, human engineered neural tissue raise the opportunity to study such a very important feature of GBM in vitro. Here, we introduce this model for studying microRNAs.