Pathophysiology of Spinal Cord Injury and Tissue Engineering Approach for Its Neuronal Regeneration: Current Status and Future Prospects.

A spinal cord injury (SCI) is a very debilitating condition causing loss of sensory and motor function as well as multiple organ failures. Current therapeutic options like surgery and pharmacotherapy show positive results but are incapable of providing a complete cure for chronic SCI symptoms. Tissue engineering, including neuroprotective or growth factors, stem cells, and biomaterial scaffolds, grabs attention because of their potential for regeneration and ability to bridge the gap in the injured spinal cord (SC). Preclinical studies with tissue engineering showed functional recovery and neurorestorative effects. Few clinical trials show the safety and efficacy of the tissue engineering approach. However, more studies should be carried out for potential treatment modalities. In this review, we summarize the pathophysiology of SCI and its current treatment modalities, including surgical, pharmacological, and tissue engineering approaches following SCI in preclinical and clinical phases.

Activated platelet-rich plasma accelerate endometrial regeneration and improve pregnancy outcomes in murine model of disturbed endometrium.

Platelet Rich Plasma (PRP) contains high concentrations of growth factors, therefore, PRP activation results in their release, stimulating the process of healing and regeneration. The study was conducted to check whether activated platelet-rich plasma (aPRP) treatment can improve regeneration of the endometrium in an experimental model of ethanol-induced disturbed endometrium. Seventy-two female Wistar rats were randomly assigned into the control group, disturbed endometrium (DE) group and aPRP treated group. Activation of PRP was performed by adding thrombin. All the animals were sacrificed on day 1, day 3, day 6 and day 9 and samples were taken from the miduterine horn. Quantification of Cytokine and chemokine profiles of activated and non-activated PRP for CCL2, TNF- α, IL-1ß, CXCL8, CXCL10, IL2, IL4, IL-6 IL-10, IL-12, IL-17A, TGF- ß, IFN-γ was carried out. Functional and structural recovery of the endometrium was analyzed by hematoxylin-eosin (HE) and immunohistochemical (IHC) analyses. HE confirmed proliferated epithelial lining and stromal reconstruction with decreased fibrosis in PRP treated group compared to the DE group. Epithelial thickness in aPRP treated on day 1, day 3, day 6 and day 9 revealed an significant increase (p ≤ 0.05). Significantly stronger IHC expression of alpha smooth muscle actin, Cytokeratin 18, Cytokeratin 19, Connexin-40, E-Cadherin, Claudin-1, Zona Occludin-1was found in the aPRP treated group compared to the DE group. Furthermore, aPRP treatment was associated with birth of live pups. Our results suggest that intrauterine administration of aPRP stimulated and accelerated the regeneration of endometrium in the murine model of disturbed endometrium.

Silver-doped hydroxyapatite laden chitosan-gelatin nanocomposite scaffolds for bone tissue engineering: an in-vitro and in-ovo evaluation.

Despite the advancements in bone tissue engineering, the majority of implant failures are caused due to microbial contamination. So, efforts are being made to develop biomaterial with antimicrobial property enhancing the regeneration of damaged bone tissue. In the present study, chitosan-gelatin (CG) scaffolds containing silver-doped hydroxyapatite (AgHAP) nanoparticles at 0.5%, 1.0% and 1.5% (w/v) were fabricated by lyophilization technique. The results confirmed the synthesis of AgHAP nanoparticles and showed interconnected porous structure of the nanocomposite scaffolds with 89%-75% porosity. Similarly, the swelling percentage, degradation behavior and compressive modulus of CG-AgHAP nanocomposite scaffolds were 1666%, 40% and 0.7 MPa, respectively. The developed nanocomposite scaffolds revealed better antimicrobial properties and bioactivity. The cell culture studies showed favorable viability of Wharton's jelly stem cells on CG-AgHAP nanocomposite scaffolds. CAM (chorioallantoic membrane) assay determined the angiogenic potential with better visualization of blood vessels in the CAM area. Hence, the obtained results confirmed that CG-AgHAP3 nanocomposite scaffold was the most suitable for bone tissue engineering applications among all scaffolds.

Cerium oxide nanoparticles disseminated chitosan gelatin scaffold for bone tissue engineering applications.

Cell-free and cell-loaded constructs are used to bridge the critical-sized bone defect. Oxidative stress at the site of the bone defects is a major interference that slows bone healing. Recently, there has been an increase in interest in enhancing the properties of three-dimensional scaffolds with free radical scavenging materials. Cerium oxide nanoparticles (CNPs) can scavenge free radicals due to their redox-modulating property. In this study, freeze-drying was used to fabricate CG-CNPs nanocomposite scaffolds using gelatin (G), chitosan (C), and cerium oxide nanoparticles. Physico-chemical, mechanical, and biological characterization of CG-CNPs scaffolds were studied. CG-CNPs scaffolds demonstrated better results in terms of physicochemical, mechanical, and biological properties as compared to CG-scaffold. CG-CNPs scaffolds were cyto-friendly to MC3T3-E1 cells studied by performing in-vitro and in-ovo studies. The scaffold's antimicrobial study revealed high inhibition zones against Gram-positive and Gram-negative bacteria. With 79 % porosity, 45.99 % weight loss, 178.25 kPa compressive modulus, and 1.83 Ca/P ratio, the CG-CNP2 scaffold displays the best characteristics. As a result, the CG-CNP2 scaffolds are highly biocompatible and could be applied to repair bone defects.

Surgical cotton microfibers loaded with proteins and apatite: A potential platform for bone tissue engineering.

Tissue engineering has emerged as the best alternative to replacing damaged tissue/organs. However, the cost of scaffold materials continues to be a significant obstacle; thus, developing inexpensive scaffolds is strongly encouraged. In this study, cellulose microfibers (C), gelatin (G), egg white (EW), and nanohydroxyapatite (nHA) were assembled into a quaternary scaffold using EDC-NHS crosslinking, followed by freeze-drying method. Cellulose microfibers as a scaffold have only received a limited amount of research due to the absence of an intrinsic three-dimensional structure. Gelatin, more likely to interact chemically with collagen, was used to provide a stable structure to the cellulose microfibers. EW was supposed to provide the scaffold with numerous cell attachment sites. nHA was chosen to enhance the scaffold's bone-bonding properties. Physico-chemical, mechanical, and biological characterization of scaffolds were studied. In-vitro using MG-63 cells and in-ovo studies revealed that all scaffolds were biocompatible. The results of the DPPH assay demonstrate the ability of CGEWnHA to reduce free radicals. The CGEWnHA scaffold exhibits the best properties with 56.84 ± 28.45 µm average pore size, 75 ± 1.4 % porosity, 39.23 % weight loss, 109.19 ± 0.98 kPa compressive modulus, and 1.72 Ca/P ratio. As a result, the constructed CGEWnHA scaffold appears to be a viable choice for BTE applications.