Dual Functionalized Injectable Hybrid Extracellular Matrix Hydrogel for Burn Wounds.

Low strength and rapid biodegradability of acellular dermal matrix (ADM) restrict its wider clinical application as a rapid cell delivery platform in situ for management of burn wounds. Herein, the extracted ADM was modified by a dual cross-linking approach with ionic crosslinking using chitosan and covalent cross-linking using an iodine-modified 2,5-dihydro-2,5-dimethoxy-furan cross-linker, termed as CsADM-Cl. In addition, inherent growth factors and cytokines were found to be preserved in CsADM-Cl, irrespective of ionic/covalent crosslinking. CsADM-Cl demonstrated improvement in post crosslinking stiffness with a decreased biodegradation rate. This hybrid crosslinked hydrogel supported adhesion, proliferation, and migration of human foreskin-derived fibroblasts and keratinocytes. Also, the angiogenic potential of CsADM-Cl was manifested by chick chorioallantoic membrane assay. CsADM-Cl showed excellent antibacterial activity against Escherichia coli and Staphylococcus aureus. Moreover, CsADM-Cl treated full thickness burn wounds and demonstrated rapid healing marked with superior angiogenesis, well-defined dermal-epidermal junctions, mature basket weave collagen deposition, and development of more pronounced secondary appendages. Altogether, the bioactive CsADM-Cl hydrogel established significant clinical potential to support wound healing as an apt injectable antibacterial matrix to encounter unmet challenges concerning critical burn wounds.

Bilayered nanofibrous 3D hierarchy as skin rudiment by emulsion electrospinning for burn wound management.

Mimicking skin extracellular matrix hierarchy, the present work aims to develop a bilayer skin graft comprising a porous cotton-wool-like 3D layer with membranous structure of PCL-chitosan nanofibers. Emulsion electrospinning with differential stirring periods of PCL-chitosan emulsion results in development of a bilayer 3D structure with varied morphology. The electrospun membrane has fiber diameter ∼274 nm and pore size ∼1.16 µm while fluffy 3D layer has fiber diameter ∼1.62 µm and pore size ∼62 µm. The 3D layer was further coated with collagen I isolated from Cirrhinus cirrhosus fish scales to improve biofunctionality. Surface coating with collagen I resulted in bundling the fibers together, thereby increasing their average diameter to 2.80 µm and decreasing pore size to ∼45 µm. The architecture and composition of the scaffold promotes efficient cellular activity where interconnected porosity with ECM resembling collagen I coating assists cellular adhesion, infiltration, and proliferation from initial days of fibroblast seeding, while keratinocytes migrate on the surface only without infiltrating in the membranous nanofiber layer. Anatomy of the scaffold arising due to variation in pore size distribution at different layers thereby facilitates compartmentalization and prevents initial cellular transmigration. The scaffold also assists in extracellular matrix protein synthesis and keratinocyte stratification in vitro. Further, the scaffold effectively integrates and attaches with third-degree burn wound margins created in rat models and accelerates healing in comparison to standard Tegaderm dressing™. The bilayer scaffold is thus a promising, readily available, cost-effective, off-the-shelf matrix as a skin substitute.

Analysis of Carcinogenic Heavy Metals in Gallstones and its Role in Gallbladder Carcinogenesis.

PURPOSE: Gallstone is a high-risk factor for gallbladder pre-malignancy or malignancy (GB PM-M) but which substances of gallstones definitely assist to turn out in to GB PM-M, remains unclear. This study aimed to find out the presence of carcinogenic heavy metals in gallstones and to explore the aetiopathogenesis of gallbladder pre-malignancy and malignancy. METHODS: Presence of elements in gallstones was detected by energy dispersive X-ray spectroscopy (EDS) with scanning electron microscopy (SEM) and then level of carcinogenic heavy metals was estimated in gallstones using atomic absorption spectroscopy (AAS). The experiment was carried out in gallstone samples of 46 patients with gallbladder pre-malignant and malignant condition (PM-M group) and 65 sex and age-matched patients with chronic cholecystitis (C-C group). Gallstones were also classified in to three types such as cholesterol stone, mixed stone, and black pigment stone. RESULTS: EDS analysis detected presence of mercury, lead, and cobalt elements in all types of gallstones of both PM-M and C-C groups. AAS analysis revealed significantly higher amount of mercury (p < 0.001), lead (p < 0.0001), cobalt (p < 0.01), and cadmium (p < 0.01) in the gallstones of PM-M than C-C groups. The presence of these heavy metals also varied among stone types of both groups. EDS phase analysis showed 'dense deposits' of these metals in gallstones. CONCLUSIONS: Presence of significantly higher amount of mercury, lead, cobalt, and cadmium in gallstones may play a pivotal role as risk factors in the development of gallbladder malignancy or pre-malignancy. 'Dense deposits' of these metals in the gallstones which is the first observation, may act as crucial doses of carcinogens.

Nano-/Microfibrous Cotton-Wool-Like 3D Scaffold with Core-Shell Architecture by Emulsion Electrospinning for Skin Tissue Regeneration.

Electrospun nanofibrous scaffold has long been studied as skin substitutes for their structural resemblance to the dermal extracellular matrix. However, packed fibrous architecture with small pore size restricts cellular infiltration into nanofibrous mat. In this article, we report highly porous, nano-/microfibrous 3D structure using polycaprolactone-chitosan emulsion and its application in skin regeneration. Under the influence of electric field, the emulsion containing encapsulated charged chitosan droplets enhances charge of the spinning solution and residual charge in the core of the deposited fiber, thereby creating core-shell, cotton-like fluffy structure with average pore size 62 µm, fiber diameter ∼1.62 µm, contact angle of 72° and 80% water uptake capacity of the scaffold. Further, differential stirring period of the specific emulsion developed compact nanofibrous membrane with nanometer ranged pore size emphasizing the role played by emulsion droplet size and the charge carried thereafter. Presence of nanofibers with high-interconnected porosity promoted efficient cellular infiltration and proliferation from initial days of cell seeding. The scaffold supported extracellular matrix protein expression and stratified epithelialization in vitro. Effective integration and attachment of scaffold with margins of a full-thickness excision wound created in a rat model with accelerated healing within 3 weeks proved the efficiency of the scaffold as skin substitute. Additionally, gradual and prolong release of acidic chitosan from the core section benefitted wound healing by lowering the pH of wound environment. Simple technique with inexpensive raw materials endorsed the scaffold as a promising off-the-shelf matrix for skin tissue regeneration.

Finding an optimum immuno-histochemical feature set to distinguish benign phyllodes from fibroadenoma.

PURPOSE: Benign phyllodes and fibroadenoma are two well-known breast tumors with remarkable diagnostic ambiguity. The present study is aimed at determining an optimum set of immuno-histochemical features to distinguish them by analyzing important observations on expressions of important genes in fibro-glandular tissue. METHODS: Immuno-histochemically, the expressions of p63 and α-SMA in myoepithelial cells and collagen I, III and CD105 in stroma of tumors and their normal counterpart were studied. Semi-quantified features were analyzed primarily by ANOVA and ranked through F-scores for understanding relative importance of group of features in discriminating three classes followed by reduction in F-score arranged feature space dimension and application of inter-class Bhattacharyya distances to distinguish tumors with an optimum set of features. RESULTS: Among thirteen studied features except one all differed significantly in three study classes. F-Ranking of features revealed highest discriminative potential of collagen III (initial region). F-Score arranged feature space dimension and application of Bhattacharyya distance gave rise to a feature set of lower dimension which can discriminate benign phyllodes and fibroadenoma effectively. CONCLUSIONS: The work definitely separated normal breast, fibroadenoma and benign phyllodes, through an optimal set of immuno-histochemical features which are not only useful to address diagnostic ambiguity of the tumors but also to spell about malignant potentiality.