Journal of Tissue Science and Engineering

The current increase in the utilization of polyhydroxyalkanoates (PHAs) in various industrial and biomedical applications is due to their biodegradability, compatibility, resorbability and piezoelectricity. In the present study, we developed a modified medium chain length PHAs (Mmcl-PHA) by sterilizing surfaces of PHAs extracted from bacterial isolate. FTIR analysis of the neat polymer confirmed the presence of functional groups corresponding to alkyl halide, alkyne, hydroxyl group, and alkane groups. Sterilization of PHA using ethylene oxide as a medium was resulted modification of minor band differences in the absorption spectrum of homopolymer of PHB (scl-PHA) in to the co polymer of P (HB-co-HV) medium chain (mcl-PHA). The variation on to carbonyl (C=O) ester groups modified without significant changes to physico-chemical properties of the polymer were noticed. Sterilization of PHA using ethylene oxide has been evident surface modification properties suited to tissue engineering application of scaffold fabrication.

The aim of the present study was to test the efficacy of cis-coordinated complexes of platinum (II) with the polymer of benzene-poly-carboxylic acids derived from lignin (CDBPA) (laboratory code BP-C1), an innovative anticancer compound, on the growth of several solid human cancer cell lines: bladder cancer, chondrosarcoma, colonic cancer, head and neck cancer, hepatic cancer, ovary cancer, pancreatic cancer and prostatic cancer. Furthermore, the effect of CDBPA on non-Hodgkin lymphoma cell lines was also tested. The effect of CDBPA on cell viability was detected by XTT assay and toxicity was detected by measuring the leakage of Lactate dehydrogenase from the cells to the media. The present study has demonstrated that CDBPA is not toxic and able to reduce cell viability substantially and significantly in various human cancer cell lines. When comparison of viability in percentage of the controls at the maximum given dose of CDBPA for each type of cancer cell line, it was found that the largest impact on the viability was on sarcoma, and then decreases via breast, prostatic, head and neck-, pancreatic, colonic cancer and finally ovarian cancer. In addition, the effect of CDBPA on non-Hodgkin lymphoma cell lines was similar to that found in sarcoma cells. We conclude that the effect of CDBPA on cell viability is different and may be dependent on genotype of the cancer cell type. This may indicate different mechanisms of action in the different cancer types. The results obtained from the in vitro studies are important for designing future in vivo studies using animal models and to predict the clinical outcome in human cancer.

Introduction: Tendinopathies are the most frequent causes of chronic shoulder pain. Long head of the biceps (LHB) tendon lesions are often associated with massive rotator cuff (RC) tears. Palliative LHB tenotomy decreases RC disease patient’s pain and disability. The aim of this work was to identify the biological changes of LHB in RC disease and assess its association with clinical manifestations.
Methods: RC disease patients submitted to LHB tenotomy were evaluated using a clinical protocol in order to retrieve information regarding shoulder pain duration and intensity (visual analogue scale) and shoulder function (Constant score). LHB tendon samples from these patients were compared with cadaver controls. Tendon tissue was qualitatively studied by conventional histology and immunohistochemistry was used to access semi quantitatively the presence of substance P and calcitonin gene-related peptide (CGRP). Tendon cell cultures were used to determine the gene expression of several extracellular matrix genes with and without stimulation with transforming growth factor (TGF)-β, TNF, IL-10 or dexamethasone.
Results: Histologically, LHB tendon from RC patients and cadaver controls had similar characteristics. RC patients had a significantly higher CGRP immunohistochemistry score as compared to controls (p=0.010) but there was no correlation with patient clinical features. On the contrary, regarding substance P no differences were found between RC patients and controls immunohistochemistry score but a correlation with shoulder pain (r=0.828, p=0.021) was identified. Through gene expression analysis we found a downregulation of the extracellular matrix genes type I collagen and thrombospondin 4, as well as vascular endothelial growth factor (VEGF) and nerve growth factor (NGF) in Manuscript Click here to download Manuscript manuscript.docx 2 patients with RC disease. However, in vitro stimulation of RC tenocytes with TGF-β rescued their ability to produce type I collagen and VEGF.
Conclusion: LHB tendon from RC disease patients had neurotransmitter disturbances that could be related to shoulder pain. Moreover, we demonstrated that LHB from RC disease patients had a downregulation of extracellular matrix genes, as well as of VEGF and NGF genes. We showed that TGF-β can partially normalize the expression of these genes, suggesting that modulating TGF-β could be a therapeutic opportunity for improving tendon quality in the context of chronic tendinopathies.

Congenital defects of the urinary bladder that requires surgical intervention with mechanical wounding are common situations among pediatric urology patients. In conditions with severe lack of tissue, regenerative medicine with autologous cells has become a field of interest for future cure. In both situations, normal bladder wound healing is of major importance for an uneventful healing process and for the final results. Much effort has been put into increasing our understanding in the area of urinary bladder wound healing. Several methods have been used in different studies, all representing different clinical settings to address the issue of normal healing. However, little is known about the differences between these different wound-healing models. In this review, we aimed at summarizing what is known about the process of bladder wound healing after mechanical injury. We present the most commonly used methods in this area; describe the process of healing and the current knowledge on involved signaling transduction factors.

Aim: To assess pain in patients with venous leg ulcer receiving compression therapy with Unna’s boot.
Methods: This was a clinical, analytical, descriptive study conducted from June 2010 to May 2011 with 50 patients with venous leg ulcers. The visual analog scale (VAS) and McGill Pain Questionnaire (MPQ) were used to assess pain at inclusion (baseline) and after 4, 8 and 12 months of treatment.
Results: The mean VAS score was 6.70 (severe pain) at baseline, 5.02 (moderate pain) at 4 months, and 0 (no pain) at 8 and 12 months, with significant difference between time points. All patients described their pain on the MPQ as sensory, affective, and miscellaneous at baseline. However, after 4 months of Unna’s boot treatment, 10 (20%) patients reported sensory pain, 46 (92%) had miscellaneous pain and 44 (88%) experienced affective pain, with significant difference between time points.
Conclusion: Patients with venous leg ulcers reported improvement in pain following treatment with Unna’s boot.

The field of tissue engineering is still seeking a viable substitute to repair and replace damaged bone using a combination of porous implants, biochemical factors, and relevant cell types. While progress in this field has been made, current engineered solutions have not been able to mimic the architectural and biological requirements needed to provide a complete solution. In this work, bone-like human osteosarcoma cells were encapsulated inside gelatin methacrylate (GelMA) hydrogels of three different weight/volume (w/v) concentrations and stimulated to form mineral in order to determine the relationship between both bone formation and cellular activity with matrix stiffness. Distinct differences between cell morphology and mineral formation were found within the three types of hydrogels. Softer, less dense constructs were shown to provide a more cell friendly microenvironment that promoted dispersed mineral formation while stiffer, dense constructs provided a more structured environment for uniform bone-mineral formation. Additionally, while cells were able to function in all three types of hydrogels, cells in the softer GelMA constructs were shown to grow in large colonies within the gelatin matrix while cells in the stiffer GelMA constructs tended to aggregate and grow along the construct peripheries.

A mixture of agarose, MEM IX and HeLa cells (dubbed Bio-Ink) was created to allow normal cell interaction with the scaffold material (agarose) before crosslinking as an initial step in 3D printing tissue. Bio-Ink was developed successfully as an in situ-scaffolding material for engineering biological structures. Bio-Ink has been further conditioned by adjusting agarose composition and gelling time to obtain optimal HeLa cell growth. After detailed study, the time range available for printing this material, before full crosslinking occurs, was determined to be about 300 s, giving it attractive properties for 3D printing. Repeatable 10 mm thick prints were successful, although more system calibration is still needed to achieve more complex prints.

Sweetpotato is an important food crop in the world as well as in Kenya. Various fungal, and viral diseases are major constraints in its production and are currently threatening the sweetpotato production in sub-Saharan Africa. Genetic engineering offers significant potential for the crop’s genetic improvement. However, this is limited by the low efï¬Âciency and strong genotype dependency in tissue culture. This study aimed to establish an efficient somatic embryogenesis and plant regeneration system using shoot apical meristem explants of sweetpotato. Three sweetpotato cultivars that are widely grown in Kenya; KSP36, Kemb36 and Mweu mutheke along with an exotic model cultivar Jewel were evaluated. The maximum somatic embryogenic induction, at 96.72%, was obtained from explants cultured on Linsmaier and Skoog salts and vitamins medium supplemented with 0.5 mg/l dichlorophenoxyacetic acid and 0.2 mg/l zeatin riboside. The highest number of shoot induction (33) was observed after transfer of embryonic callus to embryo maturation medium supplemented with 2 mg/l abscisic acid. Significant differences were observed between cultivars for somatic embryogenesis and plant regeneration. Jewel showed the best response, while Mweu mutheke was the least responsive under the culture conditions tested in this study. Regenerated plants were successfully rooted and grown to maturity after hardening in soil in the greenhouse. Such a robust, successful and efï¬Âcient system possesses the potential to become an important tool for crop improvement and functional studies of genes in sweetpotato.

Mesenchymal stem cells (MSCs) have gained increased attention in the treatment of injury-related cartilage damage. Most of the literature has focused on the use of bone marrow MSCs for chondrogensis; however its clinical use has presented consequences of donor site morbidity and pain as well as low cell number during harvest. Adipose tissue offers an abundant source of mesenchymal stem cells (MSCs), showing promise for the treatment of cartilaginous injuries. Numerous studies have focused on the safety and efficacy of adipose-derived mesenchymal stem cells (ADSC) in the form of the stromal vascular fraction (SVF), supporting its use in future clinical applications. While reports of ADSC potential for cartilage repair have been encouraging, the lack of standardization among studies, as well as the confusing terminology describing the different forms of ADSC presents cause for deeper investigation of those studies reporting clinical success. Overall, ADSCs show significant potential as an alternative and/or adjunctive treatment of cartilaginous injuries.

With limited regenerative capacity and most complex structural and electrophysiological properties; recapitulating the cardiac tissue is a challenging task for the researchers. The cell injection was found unreliable due to the cell loss and low retention of the transplanted cells. This could be overcome by the technique of cell sheet engineering. Scaffold free, thick, cell dense, three dimensional constructs could be generated for suture free transplantation. For the generation of the cardiac constructs the neonatal cardiomyocytes and myoblasts were mostly used. They were tedious to isolate and culture and the risk of arrhythmogenic foci prevailed. Hence the concept of differentiating a suitable allogeneic cell source to myocardial lineage seemed relevant. Human umbilical cord mesenchymal stem cells (hUCMSCs) are emerging with the assistance of differentiating agents and cell sheet engineering for addressing the cardiac regeneration. The preliminary report on this regard has been published. The cells attained cardiomyocyte-like morphology with the expression of alpha-actinin and myosin heavy chain on culturing with cardiac conditioned medium and the inducer sphingosine-1-phosphate. It presented cardiomyocyte-like action potential and voltage gated currents. Hence the cell sheet engineering approach with cells differentiated to cardiac lineage using specific agents is a recent area to be explored.