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The titanium nitride coated titanium is a material intended for the fabrication of left ventricular assist device. As per International standards, a material is subjected to pre-clinical evaluation before fabrication of a device. Toxicity/biocompatibility studies such as acute systemic toxicity, intracutaneous irritation, in vitro haemolysis and implantation in muscle were studied as per international standards for the titanium nitride coated titanium. Acute systemic toxicity was studied in mice using physiological saline and cotton seed oil extracts of the material. Intracutaneous irritation was done by injecting the extracts of the test material and control intradermally into rabbits. Grading of erythema and oedema of test and control animals were recorded at 24, 48 and 72 h. In vitro haemolysis was carried out with material and extract of the material with rabbit blood. The muscle implantation was carried out in nine anesthetized rabbits. The implanted animals were sacrificed at the end of 1, 4 and 12 weeks, the tissue with the implanted materials were collected and subjected to histopathological analysis. The results of the study did not show any significant irritation or systemic toxicity with physiological saline and cotton seed oil extracts of the material. The percentage of hemolysis induced by the material and extract was under acceptable range. Results of the histopathological evaluation suggest that the test material did not produce any cellular changes. Hence the present study concluded that the test material is non-toxic, non-irritant, non-haemolytic and biocompatible.

Compromised angiogenesis is a major factor contributing delayed wound healing in diabetic patients. Graftassisted healing using synthetic and natural scaffolds supplemented with micromolecules for stimulating angiogenesis is the contemporary tissue engineering strategy for treating diabetic wounds. This study deployed the carbodiimide chemical reaction for coupling gelatin with a porcine cholecyst-derived scaffold (CDS) for enhancing angiogenesis. The modification was confirmed by the trinitrobenzene sulfonic acid assay and scanning electron microscopy. The gelatin-coupled CDS was more stable than the bare CDS in an in vitro proteolytic environment and allowed survival of keratinocytes (HaCaT), indicating its suitability for chronic skin wound application. The gelatin coupling brought significant improvement in the in vitro angiogenic potential of the CDS as evident from the enhanced viability of endothelial cells. An in ovo chorioallantoic membrane assay also demonstrated the angiogenic potential of the modified scaffold. Further, the modified scaffold promoted angiogenesis and aided faster healing of full-thickness excision wounds in streptozotocin-induced diabetic rats. It is concluded that the gelatin-coupled CDS is a potential advanced wound care material for treating diabetic wounds.

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Oxidative stress is involved in diverse biological phenomenon, and is caused by the imbalance between reactive oxygen species (ROS) and antioxidant defense system. 8-Hydroxy-2'-deoxyguanosine (8-OHdG) is the most critical biomarker in the estimation of ROS-induced DNA damage. This investigation focuses on the effect of fibrin glue on lipid peroxidation (LPO), antioxidant enzymes and oxidative DNA damage (both in vitro and in vivo). The blood biochemical parameters of the implanted animals and in vitro chromosomal aberrations were also studied. Fibrin glue was applied on the calvarial defect made on the anesthetized rats for an observation period of 4, 12, 26 and 52 weeks. At the end of the observation period, animals were anesthetized; blood was collected for serum analysis and was sacrificed. Brain was collected for the detection of 8-OHdG using competitive ELISA and liver was collected for analyzing the antioxidant enzymes and LPO. The results of this study suggest that the effect of fibrin glue on rat brain (in vivo and in vitro) and mice liver (in vitro) did not make any significant influence on LPO and antioxidant defense system. Similarly, there was no change observed in the expression of 8-OHdG. Serum constituents of implanted rats were observed to be within the normal range. The normal karyotype obtained indicates that the physiological saline extract of fibrin glue does not induce any chromosomal anomalies. Hence, it was concluded that the fibrin glue material does not have any potential to produce oxidative stress, alterations in the C-8 position of guanine and chromosomal anomalies.

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Graft-assisted healing is often proposed for clinical management of large-sized third-degree cutaneous burn wounds. Skin-graft substitutes prepared by loading appropriate cell types on suitable scaffolds have been found successful. We have previously shown that cholecyst-derived scaffold prepared by a non-detergent/enzymatic method can be used as skin-graft substitute for promoting healing of full thickness excision wounds in rabbit. This article examines the use of this scaffold for preparing bio-artificial grafts by loading homologous fibroblasts. The healing potential was evaluated in a rabbit model of full thickness skin-burn wound. The healing process was evaluated by gross morphology evaluation and histomorphology evaluation at 7, 14 and 28 days of healing. Ex vivo imaging of the wounded tissue was performed and it was found that the loaded fibroblasts remained viable at least for 14 days in the healing wound. By the first week, re-epithelialisation was evident in all animals treated with the cell-loaded graft. Histomorphological wound healing parameters such as the quickness of re-epithelialisation, the nature of collagen deposition and the extent of neo-vascularisation indicated that cell-loaded grafts promoted faster healing of the wounds. Results of immunohistochemistry indicated a parallel change in the number of proliferating cells and myofibroblast in the healing tissue. Although the pathophysiology of the healing reaction was not established, the observations suggested that homologus fibroblast-loaded cholecyst-derived scaffold promoted faster healing of third-degree wounds in rabbit model by modulating myofibroblast response. It was concluded that cholecyst-derived scaffold prepared by the non-detergent/enzymatic method is a potential scaffold for fabricating bioartificial skin grafts.

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