Decellularized Caprine Conchal Cartilage toward Repair and Regeneration of Damaged Cartilage.

Repair and regeneration of nasal and auricular cartilage thrust significant challenges in reconstructive surgery. The burgeoning clinical requirement is yet to endorse a satisfactory cartilage replacement matrix. In this regard, we have bioengineered cross-linked decellularized caprine conchal cartilage (DC) as biocompatible, durable, and nontoxic matrices. The DC matrices exhibited reduced DNA and sulfated glycosaminoglycan (sGAG) with a minimal effect on the collagen content. Further, histology and scanning electron micrographs revealed a significant loss of cellular bodies and the presence of a compact matrix consisting of intricate collagen fibers, when compared to unprocessed matrices. An in vitro biological assessment of the matrices exhibited an increased chondrocyte proliferation and viability with a significantly higher DNA, sGAG, and total collagen content. The matrices showed a 3-fold increase in the expression of cartilage-specific genes, namely, aggrecan, collagen II, and sox-9, and exhibited a minimal in vitro immunogenicity. Further, an in vivo assessment was performed by xenografting these caprine matrices in a rabbit model. The retrieved matrices showed a well-organized structural and cellular orientation with extracellular matrix formation after 3 months of implantation. No significant infiltration of plasma cells, macrophages, lymphocytes, and immature fibroblasts was recorded. Therefore, these affordable, resourceful, xenocompatible matrices offer a potential alternate in the repair and regeneration of nasal and auricular cartilages.

Novel decellularized animal conchal cartilage graft for application in human patient.

Restoration of the external ear and nose in human patients, in either congenital deformity or acquired defects, is a challenge in reconstructive surgery. Optimization of the currently available materials is necessary for rhinoplasty and microtia correction to avoid intraoperative manoeuvring and early rejection. The aim of this study was to develop cross-linked decellularized caprine conchal cartilages as biocompatible, robust, and non-toxic matrix template. The characterization of the decellularized tissue encompasses in vitro lymphoproliferation assay, cytotoxicity test, agar gel precipitation test, in vivo immunocompatibility study, histology, and determination of pro-inflammatory cytokines in animal model. Decellularized cartilage was implanted in human volunteer at R. G. Kar Medical College and Hospital, Kolkata, India, and samples were assessed histologically by retrieving those after 4 months. The processed cartilages were implanted in rhinoplasty (nine) and microtia patients (six) keeping autogenous cartilage graft as control up to 18 months after surgery. Primary outcomes were viability and safety of the material, both in animal model and human pre-application in actual site. Secondary outcomes included self-assessed clinical findings on gross examination. This study is under the ethical approval no. RKC/14 dated January 27, 2012. The in vitro cellular reactivity was less in processed cartilage protein than control. Histology of retrieved tissues in animal model and human volunteer showed no adverse reactions. Production of IL-2, IL-6, and TNF-α cytokines was lower at 4 weeks. The rhinoplasty and microtia operation in clinical patients utilizing the processed cartilage showed satisfactory recovery with improved facial look. These low cost, easily available, biocompatible, safe xenocartilage biomatrices of caprine conchal cartilage origin are very flexible in shape and size, enabling them as potential bioimplant for repair of nasal and auricular structure without any rejection or diverse biomedical applications.

Evaluation of facial artery perforator-based flaps in reconstruction of facial defects.

INTRODUCTION: Several flaps have been described for reconstructing facial or oral defects. Flaps such as forehead and pectoralis major are often too bulky for small-to-moderate-sized defects, for which nasolabial flaps are often ideal. However, nasolabial flaps have limited mobility and reach and may need two stages, particularly for intraoral defects. According to recent literatures, facial artery provides numerous small cutaneous perforators, based on which skin flaps can be islanded, with greater mobility and reach for reconstruction of small-to-moderate-sized intraoral and facial defects in one stage. Our study aims to evaluate the reliability and versatility of facial artery perforator-based flaps in the reconstruction of such defects. MATERIALS AND METHODS: A ethical committee-approved retrospective study was conducted on data of the patients attending our outpatient department between February 2014 and October 2015 with small-to-moderate-sized facial/oral lesions. The total sample size was 23. We studied the relation of flap survival with size of flap, route of inset and neck dissection, functional and aesthetic outcomes and feasibility of adjuvant therapy in cases of malignancies. RESULTS AND ANALYSIS: A wide range of facial defects, especially intraoral defects, could be reconstructed in one stage using facial artery perforator-based flaps. The flaps were reliable. Complications included only partial skin loss of the flaps in a few cases. Complications were directly related to the length of the flaps and the route of inset. Functional and aesthetic outcomes were satisfactory and none of the flaps showed any significant post-radiotherapy changes. CONCLUSIONS: We concluded that facial artery perforator flap can be a simple, safe, versatile and one-stage alternative to the traditional flaps in the reconstruction of small-to-moderate-sized facial defects. Neck dissection can be safely done in the same sitting.

Systematic approach to treat chronic osteomyelitis through localized drug delivery system: bench to bed side.

Chronic osteomyelitis is a challenging setback to the orthopedic surgeons in deciding an optimal therapeutic strategy. Conversely, patients feel frustrated of the therapeutic outcomes and development of adverse drug effects, if any. Present investigation deals with extensive approach incorporating in vivo animal experimentation and human application to treat chronic osteomyelitis, using antibiotic loaded porous hydroxyapatite scaffolds. Micro- to macro-porous hydroxyapatite scaffolds impregnated with antibiotic ceftriaxone-sulbactam sodium (CFS) were fabricated and subsequently evaluated by in vivo animal model after developing osteomyelitis in rabbit tibia. Finally 10 nos. of human osteomyelitis patients involving long bone and mandible were studied for histopathology, radiology, pus culture, 3D CT etc. up to 8-18 months post-operatively. It was established up to animal trial stage that 50N50H samples [with 50-55% porosity, average pore size 110 µm, higher interconnectivity (10-100 µm), and moderately high drug adsorption efficiency (50%)] showed efficient drug release up to 42 days than parenteral group based on infection eradication and new bone formation. In vivo human bone showed gradual evidence of new bone formation and fracture union with organized callus without recurrence of infection even after 8 months. This may be a new, alternative, cost effective and ideal therapeutic strategy for chronic osteomyelitis treatment in human patients.

Macro-to-micro porous special bioactive glass and ceftriaxone-sulbactam composite drug delivery system for treatment of chronic osteomyelitis: an investigation through in vitro and in vivo animal trial.

A systematic and extensive approach incorporating in vitro and in vivo experimentation to treat chronic osteomyelitis in animal model were made using antibiotic loaded special bioactive glass porous scaffolds. After thorough characterization for porosity, distribution, surface charge, a novel drug composite were infiltrated by using vacuum infiltration and freeze-drying method which was subsequently analyzed by SEM-EDAX and studied for in vitro drug elution in PBS and SBF. Osteomyelitis in rabbit was induced by inoculation of Staphylococcus aureus and optimum drug-scaffold were checked for its efficacy over control and parenteral treated animals in terms of histopathology, radiology, in vivo drug concentration in bone and serum and implant-bone interface by SEM. It was optimized that 60P samples with 60-65% porosity (bimodal distribution of macro- to micropore) with average pore size ~60 µm and higher interconnectivity, moderately high antibiotic adsorption efficiency (~49%) was ideal. Results after 42 days showed antibiotic released higher than MIC against S. aureus compared to parenteral treatment (2 injections a day for 6 weeks). In vivo drug pharmacokinetics and SEM on bone-defect interface proved superiority of CFS loaded porous bioactive glass implants over parenteral group based on infection eradication and new bone formation.

Development of new localized drug delivery system based on ceftriaxone-sulbactam composite drug impregnated porous hydroxyapatite: a systematic approach for in vitro and in vivo animal trial.

PURPOSE: Present investigation deals with an extensive approach incorporating in vitro and in vivo experimentation to treat chronic osteomyelitis, using hydroxyapatite porous scaffolds. MATERIALS AND METHODS: Hydroxyapatite was synthesized in the laboratory by wet chemical method, different porous scaffolds have been fabricated. In vitro studies include variation of porosity with interconnectivity, pore-drug interfacial studies by SEM-EDAX and drug elution studies (by HPLC) both in contact with PBS and SBF at approximately 37 degrees C. In vivo trials were based on experimental osteomyelitis in rabbit model induced in tibia by Staphylococcus aureus. Characterizations included observation of histopathology, radiology and estimation of drug in both bone and serum for 42 days by HPLC method and subsequent bone-biomaterial interface by SEM. RESULTS: It was established that lower pore percentage with a distribution of mainly micro-pores were found to be superior over the higher pore percentage both in vitro and in vivo. The criteria was matched with the 50N50H samples which had 50-55% porosity with an average pore size approximately 110 microm, having higher interconnectivity (10-100 microm), moderately high adsorption efficiency (approximately 50%) when loaded with CFS (drug combinations consisting of irreversible b-lactamase inhibitor and b-lactam antibiotic). CFS release from HAp implants were faster in PBS than SBF. Further, both the results of in vitro and in vivo drug elution after 42 days showed release higher than minimum inhibitory concentration of CFS against Staphylococcus aureus. In vivo studies also proved the superiority of CFS loaded HAp implants than parenteral group based on eradication of infection and new bone formation. CONCLUSIONS: HAp based porous scaffold loaded with CFS and designed porosity (in terms of micro- and macro-porosity, interconnectivity) was found to be an ideal delivery system which could locally, sustainably release the composite antibiotic in reliable manner both in terms of in vitro drug elution behaviour in contact with SBF and in vivo animal trial.