The study of miRNA-200c expression and epithelial-to-mesenchymal transition-related transcription factors in the primary bladder urothelial carcinoma.

Background: Epithelial-mesenchymal transition (EMT) plays an important role in bladder carcinoma (BC) invasiveness and metastasis. Studies have shown that muscle-invasive BC (MIBC) and non-MIBC (NMIBC) are different at the molecular level owing to different EMT-related programming. Recent studies suggest that dysregulation of specific miRNAs is linked to EMT in BC. With this background, we aimed to study the immunoexpression of EMT-markers and its correlation with miRNA-200c expression in a series of MIBCs and NMIBCs. Materials and Methods: Quantitative real-time-polymerase chain reaction for the quantification of miR-200c expression was performed on 50 cases of urinary BC obtained from transurethral resection of bladder tumor (TURBT), cystectomy specimens, and ten peritumoral bladder tissue. Immunohistochemistry for ZEB1, ZEB2, TWIST, E-cadherin, and ß-catenin was performed on tumor and peritumoral bladder tissue. Results: Thirty-five TURBT and 15 cystectomy specimens were assessed. Among MIBC, loss of expression of E-cadherin (72.3%), ß-catenin (66.7%), and ZEB1, ZEB2, and TWIST2 immunoreactivity was noted in 53.3%, 86.7%, and 73.3% of cases, respectively. Among NMIBC, loss of expression of E-cadherin (22.5%), ß-catenin (17.1%) and ZEB1, ZEB2, and TWIST immunoreactivity was noted in 11.5%, 51.4%, and 91.4% of cases, respectively. Upregulation of miRNA-200c was noted in cases with retained E-cadherin and negative TWIST expression. Downregulation of miRNA-200c expression was noted in all the cases showing loss of E-cadherin, ß-catenin, and in cases immunoreactive for ZEB1, ZEB2, and TWIST in MIBC. Downregulation of miRNA-200c expression was also noted in cases of MIBC with retained ß-catenin and those immunonegative for ZEB1 and ZEB2. A similar trend was noted in NMIBC. Median miRNA-200c expression was low in both high-grade and low-grade NMIBC compared to peritumoral bladder tissue and was not statistically significant. Conclusion: This study for the first time explores the relation of miR200C with E-cadherin, b-catenin, and its direct transcriptional regulators, namely Zeb1, Zeb2, and Twist in the same cohort of BC. We observed that miRNA-200c is downregulated in both MIBC and NMIBC. We identified novel expression of TWIST in cases of BC showing downregulation of miR200Cs suggesting that it is one of the protein targets of altered miRNA-200c expression contributing to EMT and can serve as a promising diagnostic marker and therapeutic target. Loss of E-cadherin and ZEB1 immunoexpression in high-grade NMIBC suggests an aggressive clinical behavior. However, ZEB2 heterogeneous expression in BC limits its diagnostic and prognostic utility.

Assessment of renal allograft rejection with diffusion tensor imaging.

OBJECTIVES: To investigate the value of DTI in differentiation of renal allograft rejection from well-functioning stable allograft, using fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values. METHODS: In this prospective study, 22 transplant recipients with well-functioning stable allograft (group A) and 20 patients with renal allograft rejection (group B + C) were recruited over a period of 19 months from January 2018 to July 2019. DTI-MRI was performed in all the patients, and FA and ADC values were measured in cortical and medullary regions of the transplanted kidney. On biopsy, graft rejection was classified as acute (group B) (n = 7) and chronic graft rejection (group C) (n = 13) based on the BANNF scoring system. Statistical analysis was performed using STATA v.14.0. RESULTS: Statistically significant difference between group A and group B + C was noted for cortical (p < 0.001), and medullary (p = 0.003) FA values, and cortical (p = 0.020), and medullary (p = 0.046) ADC values. Cortical(p < 0.001) and Medullary(p = 0.020) FA values showed statistically significant difference between group A and group C, and cortical FA value(p = 0.012) also showed statistically significant difference between group B and group C. AUC (to differentiate between renal allograft rejection and well-functioning stable allograft) for cortical, and medullary FA values and cortical and medullary ADC values were 0.853(p < 0.001), 0.757(p = 0.004), 0.709(p = 0.021) and 0.736(p = 0.009), respectively. CONCLUSION AND ADVANCES IN KNOWLEDGE: DTI is a promising functional MRI technique for the non-invasive assessment of renal allograft function. Diffusion parameters, such as FA and ADC values, can be useful in the differentiation of renal allograft rejection from well-functioning stable allograft.

Solid Lipid Nanoformulation of Berberine Attenuates Doxorubicin Triggered in vitro Inflammation in H9c2 Rat Cardiomyocytes.

AIM: The aim of this study was to evaluate the efficacy of solid lipid nanoparticles of berberine against doxorubicin-induced cardiotoxicity. BACKGROUND: Berberine (Ber) is cardioprotective, but its oral bioavailability is low, and its effect on chemotherapy-induced cardiotoxicity has not been studied. OBJECTIVE: Solid lipid nanoparticles (SLNs) of berberine chloride were prepared, characterized and evaluated in vitro against doxorubicin-induced cardiomyocyte injury. METHODS: Berberine-loaded SLNs (Ber-SLNs) were synthesized using the water-in-oil microemulsion technique with tripalmitin, Tween 80 and poloxamer 407. Ber-SLNs were evaluated for preventive effect against toxicity of doxorubicin in H9c2 cells. The culture was pre-treated (24 h) with Ber (10 µM) and Ber-SLNs (1 and 10 µM), and 1 µM of doxorubicin (Dox) was added for 3 h. The cell viability assay (MTT (3-(4,5-Dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide) and LDH (Lactate dehydrogenase)), levels of Creatine kinase-MB (CK-MB), Nitrite, MDA (Malondialdehyde), ROS (Reactive oxygen species) generation, and apoptotic DNA (Deoxyribonucleic acid) content were assessed. RESULTS: Ber-SLNs had a mean particle size of 13.12±1.188 nm, the zeta potential of -1.05 ± 0.08 mV, poly-dispersity index (PDI) of 0.317 ± 0.05 and entrapment efficiency of 50 ± 4.8%. Cell viability was 81 ± 0.17% for Ber-SLNs (10 µM) and 73.22 ± 0.83% for Ber (10 µM) treated cells in the MTT assay. Percentage cytotoxicity calculated from LDH release was 58.91 ± 0.54% after Dox, 40.3 ± 1.3% with Ber (10 µM) and 40.7 ± 1.3% with Ber-SLNs (1 µM) (p<0.001). Inflammation and oxidative stress markers were lower with Ber and Ber-SLNs. Attenuation of ROS generation and apoptosis of cardiomyocytes were noted on fluorescence microscopy. CONCLUSION: Ber SLNs effectively prevented doxorubicin-induced inflammation and oxidative stress in rat cardiomyocytes. The results demonstrate that microemulsion is a simple and costeffective technique to prepare Ber-SLNs, and may be considered as a drug delivery vehicle for berberine.

Application of elastin-like polypeptide (ELP) containing extra-cellular matrix (ECM) binding ligands in regenerative medicine.

Extracellular matrix (ECM) molecules play an important role in regulating molecular signaling associated with proliferation, migration, differentiation, and tissue repair. The identification of new kinds of ECM mimic biomaterials to recapitulate critical functions of biological systems are important for various applications in tissue engineering and regenerative medicine. The use of human elastin derived materials with controlled biological properties and other functionalities to improve their cell-response was proposed. Herein, we reported genetic encoded synthesis of ELP (elastin-like polypeptide) containing ECM domains like RGD (integrin binding ligand) and YIGSR (laminin-selective receptor binding ligand) to regulate cell behaviour in more complex ways, and also better model natural matrices. Thermal responsiveness of the ELPs and structural conformation were determined to confirm its phase transition behaviour. The fusion ELPs derivatives were analysed for mechanical involvement of growth mechanism, regenerative, and healing processes. The designed fusion ELPs promoted fast and strong attachment of fibroblast cells. The fusion ELP derivatives enhanced the migration of keratinocyte cells which of crucial for wound healing. Together it provides a profound matrix for endothelial cells and significantly enhanced tube formation of HUVEC cells. Thus, strategy of using cell adhesive ELP biopolymer emphasizing the role of bioactive ELPs as next generation skin substitutes for regenerative medicine.

Polyaspartic acid, 2-acrylamido-2-Methyl propane sulfonic acid and sodium alginate based biocompatible stimuli responsive polymer gel for controlled release of GHK-Cu peptide for wound healing.

Stimuli responsive polymer based on Polyaspartic acid, 2-Acrylamido-2-methylpropane sulfonic acid and sodium alginate (NaAlg) were synthesized using two cross-linkers Ethylene glycol dimethacrylate (EGDMA) and TMPTA (Trimethylolpropane triacrylate). The polymers were standardized and optimized to obtain a polymer with maximum swelling in distilled water, saline, glucose and solutions of varying pH. The synthesized polymer swelled well in distilled water, glucose solution and acidic- alkaline medium. The biocompatibility of the polymer was evaluated for blood compatibility and protein adsorption. The polymer with maximum swelling property was used for peptide release studies. The polymer was further used to study the peptide encapsulation and release efficiency of the polymeric material which was confirmed by FTIR, Scanning Emission Microscope and EDX. The encapsulation efficiency of the polymer for encapsulating (glycyl-l-histidyl-l-lysine-copper) GHK-Cu was observed to be 55.26% and peptide release of 51.84% was observed for Ethylene glycol dimethacrylate based polymer after 24 h whereas for Trimethylolpropane triacrylate based polymer the encapsulation efficiency was observed to be 49.6% and release was 39.01%. The EGDMA based polymer was further examined under in vivo studies in order to evaluate the efficiency of the synthesized polymer. The in vivo studies include wound closure, histopathological analysis, biochemical and toxicity assay. The material has shown promising results for both in vivo and in vitro studies.

Comparative Evaluation of Anti-Fibrotic Effect of Tissue Specific Mesenchymal Stem Cells Derived Extracellular Vesicles for the Amelioration of CCl4 Induced Chronic Liver Injury.

Mesenchymal Stem Cells (MSCs) derived Extracellular Vesicles (EVs) have emerged as an effective candidate for amelioration of liver fibrosis. However, the effect and the mechanisms of MSC-EVs in liver repair remains elusive. In this study, we have evaluated the differential regenerative efficacy of EVs derived from two different human tissue-specific MSCs (Adipose tissue; AD-MSC and Wharton's Jelly; WJ-MSC), in a murine model of chronic liver fibrosis. Mouse model of chronic liver injury was induced by carbon tetrachloride (CCl4) injection, followed by administration of EVs via the tail vein. Both quantitative and qualitative assessment was done to evaluate the hepatic regenerative potential of tissue specific MSC-extracellular vesicles. EVs, regardless of their MSC source, were found to be effective in alleviating chronic liver fibrosis, as demonstrated by macroscopic alterations in the liver. According to the findings of the comprehensive study, there were subtle variations in the tissue specific MSCs-EVs mediated approaches. A greater anti-fibrotic impact was demonstrated by AD-MSC derived EVs through extracellular matrix alteration and hepatocyte proliferation. WJ-MSC EVs, on the other hand, have an anti-inflammatory effect, as evidenced by alterations in the expression of pro- and anti-inflammatory cytokines. Furthermore, cargo profiling of these EVs revealed differences in the miRNA and protein expression, as well as the pathways that they were associated. Comparative overview of regression of fibrosis using tissue specific MSC derived EVs (credits BioRender.com ).

Mucoadhesive silver nanoparticle-based local drug delivery system for peri-implantitis management in COVID-19 era. Part 1: antimicrobial and safety in-vitro analysis.

BACKGROUND: Pseudomonas aeruginosa, a major respiratory pathogen, has been isolated from peri-implant sites and is associated with dental implant failure. This in-vitro study (part 1) aimed to fabricate a novel mucoadhesive silver nanoparticle-based local drug delivery chip, evaluate its antimicrobial efficacy against P. aeruginosa, and its safety for the treatment of peri-implantitis. MATERIALS AND METHODS: Silver nanoparticles were synthesized and characterized using a transmission electron microscope (TEM). The local drug delivery chip was fabricated using gelatin, glycerol, silver nanoparticle solution (2.5 µg/ml, 5 µg/ml, 7.5 µg/ml, and 10 µg/ml), glutaraldehyde, and sodium alginate solution. These chips were evaluated for physical parameters, effect on viability of murine macrophage cell line J774A.1, and antimicrobial activity (using Kirby-Bauer disc diffusion method with 18 h incubation period) against P. aeruginosa ATCC 27853. RESULTS: Silver nanoparticle antimicrobial chip exhibited dimensions of 4 mm × 5 mm x 0.4 mm, 5.8 mg weight, pH 5-6, folding endurance 1.04, and one-year stability. P. aeruginosa was susceptible to ≥ 7.5 µg/ml concentration of silver nanoparticles (spherical shape with particle size ranging from 10 to 100 nm). Murine macrophage cells exhibited 93% viability after 24 h incubation with silver nanoparticle chips. CONCLUSION: The novel silver nanoparticle chip showed dimensional stability, minimal effect on murine macrophage cell viability, and significant antimicrobial activity against P. aeruginosa. With the further establishment of its effective dosage and safety, this chip could be used as an adjunct to mechanical debridement (as a non-aerosol generating procedure) in treating peri-implantitis, especially during the ongoing coronavirus disease 2019 (COVID-19) pandemic.

Fabrication and evaluation of antimicrobial biomimetic nanofiber coating for improved dental implant bioseal: An in vitro study.

BACKGROUND: A weak implant-soft tissue interface may lead to bacterial ingression, breakdown of underlying tissues, and eventually implant failure. This study proposes a surface modification technique of titanium alloy (Ti), using a nano-biopolymer scaffold to enhance soft tissue attachment in dental implants. METHODS: Gelatin (20% w/v) embedded with 10 ± 2 nm silver nanoparticles (AgNPs) was electrospun to form a gelatin electrospun mat (GEM) scaffold, bonded to Ti alloy surface using chemical surface functionalization. Antimicrobial activity of AgNPs was tested against representative Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli) at 4, 24, and 48 hours and after embedding in scaffold at 48 hours. Cytotoxicity analysis (MTT assay) was performed using the 3T3 mouse fibroblast cell line at 24 and 72 hours for two groups: control (unmodified Ti disc) and experimental (GEM embedded with AgNPs); and further validated by scanning electron microscopy. RESULTS: The AgNPs-embedded GEM showed good antimicrobial activity at 48 hours, with the AgNPs showing complete (99.99%) inhibition of bacterial colony counts at 24 and 48 hours. Cell viability and proliferation over the GEM modified Ti discs were seen to be significantly increased (P < 0.05) at 72 hours as compared with control. SEM images revealed intimate spreading of fibroblasts, with differentiated cell morphology and pseudopodial processes, indicative of enhanced fibroblastic adhesion, growth, and differentiation over the scaffold. CONCLUSION: Results show good antifouling properties and biocompatibility of the fabricated coating, making it a promising strategy to reduce postoperative infections and peri-implant diseases in Ti dental implants.

Monoclonal Gammopathy of Renal Significance: Histomorphological Spectrum at a Tertiary Care Center.

Introduction: The term monoclonal gammopathy of renal significance (MGRS) has been described to include patients with renal manifestations associated with circulating monoclonal proteins with or without a clonal lymphoproliferation (B-cell or plasma cell) and not meeting diagnostic criteria for an overt hematological malignancy. A host of MGRS-associated lesions have been described that involve various renal compartments. Our study describes the histomorphological spectrum of MGRS cases at our center in the last 5 years and description as per the classification system of the International Kidney and Monoclonal Gammopathy Research Group (IKMG). Material and Methods: Retrospective analysis was carried out of all the renal biopsies with characteristic monoclonal immunoglobulin lesions for histopathological diagnosis between years 2015 and 2020 and reviewed by two independent pathologists. Results: Most patients in the study belonged to the fifth decade, with a median age of 50 years (mean 50.14 ± 10.43) range (24-68 years) with a male preponderance. Most patients presented with proteinuria as the sole manifestation (66.6%). Many of the patients (48%) had an M spike by serum protein electrophoresis or urinary protein electrophoresis with an abnormal serum free light chain assay (60.8%). AL amyloidosis was the most common diagnosis observed on histopathological evaluation (68.7%), followed by light chain deposition disease (10.4%). Conclusion: MGRS lesions are infrequently encountered in the practice of nephropathology and pose a diagnostic challenge due to the limitation of a congruent clinical or hematological picture. A thorough histological examination with immunofluorescence and electron microscopy often precipitates in the right diagnosis and prompts timely management.

Dihydromyricetin alleviates cerebral ischemia-reperfusion injury by attenuating apoptosis and astrogliosis in peri-infarct cortex.

OBJECTIVES: In ischemic stroke, reperfusion after thrombolysis is associated with secondary brain damage. Dihydromyricetin (DHM), a flavonoid, has shown neuroprotective effects through anti-oxidant, anti-inflammatory and anti-apoptotic properties. This study investigates the potential of DHM, given postreperfusion in middle cerebral artery occlusion (MCAo) model of stroke in rats. METHODS: MCAo surgery was performed in male Wistar rats. Reperfusion was performed after 90 min of ischemia. DHM (50 and 100 mg/kg) was administered 10-15 min and 2 h postreperfusion followed by daily dosing for 2 more days. Neurobehavioral parameters and infarct size (TTC staining) were assessed after 72 h. The effective dose (100 mg/kg) was then used to study reduction in infarct size (measured by MRI) and effect on apoptosis (evaluated by protein expression of Bax, Bcl-2 and cleaved caspase-3 and TUNEL assay) in peri-infarct cortex. Furthermore, effects of DHM on neuronal damage and activation of astrocytes were studied by immunofluorescence. RESULTS: Poststroke DHM (100 mg/kg) administered for 3 days showed significant improvements in motor-coordination and infarct damage (TTC staining and MRI). MCAo-induced altered apoptotic proteins were normalized to a significant extent in peri-infarct cortex with DHM treatment. Data from TUNEL assay were complementary to the effects on apoptotic proteins. Additionally, DHM caused a significant reduction in the number of reactive astrocytes when compared with the MCAo group. DISCUSSION: This study demonstrated the efficacy of subacute DHM treatment in ischemia/reperfusion injury by modulating apoptosis and astrogliosis in the peri-infarct cortex. This suggests the potential of DHM in attenuating disease progression.

KM55 in the Evaluation of IgA-Containing Glomerular Diseases.

Introduction: Mucosal-derived galactose-deficient IgA is central to the pathogenesis of primary IgA nephropathy (IgAN). Recent reports suggest similar pathogenesis in Henoch-Schonlein purpura (HSP) and secondary IgAN. Its role in other IgA-containing glomerular diseases is still under investigation. It can be detected in glomeruli with the recently described antibody KM55. We aimed to evaluate the role of KM55 by immunostaining a wide spectrum of IgA-containing glomerular diseases. Methods: After standardization and colocalization in a case of IgAN, a spectrum of 60 cases including IgAN, HSP, chronic liver disease (CLD)-related IgAN, other secondary IgAN, IgA-dominant/codominant membranoproliferative glomerulonephritis (MPGN), and lupus nephritis were subjected to immunofluorescence with KM55. KM55 was used to resolve diagnostic dilemma in cases of IgA deposition with confounding histology. Results: The group of primary IgAN (17 cases), HSP (4 cases), and secondary IgAN (19 cases) including CLD showed 2-3+ granular staining with KM55, suggesting mucosal-derived IgA. In contrast, cases of IgA-dominant/codominant MPGN (8 cases) and lupus nephritis (12 cases) were negative for KM55, suggesting systemic derivation of IgA. In cases of IgA deposition with confounding histology such as membranoproliferative or diffuse endocapillary proliferative pattern, KM55 helped to resolve the diagnosis. Discussion/Conclusion: This cross-sectional study concludes that KM55 is useful in the evaluation of IgA-containing glomerular diseases from a pathogenetic perspective and is a practical tool in resolving differential diagnosis in cases with overlapping histopathological features.

Preclinical efficacy study of a porous biopolymeric scaffold based on gelatin-hyaluronic acid-chondroitin sulfate in a porcine burn injury model: role of critical molecular markers (VEGFA, N-cadherin, COX-2), gamma sterilization efficacy and a comparison of healing potential to Integra™.

Development of scaffold from biopolymers can ease the requirements for donor skin autograft and plays an effective role in the treatment of burn wounds. In the current study, a porous foam based, bilayered hydrogel scaffold was developed using gelatin, hyaluronic acid and chondroitin sulfate (G-HA-CS). The fabricated scaffold was characterized physicochemically for pre- and post-sterilization efficacy by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA).In-vitrostudies proved that the scaffold promoted cellular proliferation. The efficacy of G-HA-CS scaffold was compared with Integra™ at different time points (7, 14, 21 and 42 days), in a swine second degree burn wound model. Remarkable healing potential of the scaffold was evident from the wound contraction rate, reduction of IL-6, TNF-αand C3. The expression of healing markers TGF-ß1 and collagen 1 revealed significant skin regeneration with regulated fibroblast activation towards the late phase of healing (p< 0.001 at day 21 and 42 vs. control). Expression of Vascular Endothelial Growth Factor A (VEGFA), vimentin and N-cadherin were found to favor angiogenesis and skin regeneration. Mechanistically, scaffold promoted wound healing by modulation of CD-45, cyclooxygenase-2 and MMP-2. Thus, the promising results with foam based scaffold, comparable to Integra™ in swine burn injury model offer an innovative lead for clinical translation for effective management of burn wound.

Glucose- regulated protein 78 (GRP78) in renal cell carcinoma: A novel biomarker for predicting tumor behavior.

OBJECTIVE: To study the mRNA and protein expression of GRP78 in tumor and serum of the RCC patients and compare with the controls and to correlate the expression with the grade and stage of RCC. MATERIALS AND METHODS: A prospective cohort study involving 60 patients planned for radical/partial nephrectomy for primary RCC between July 2017 to June 2019. The RCC and adjacent non-tumorous renal tissues (Control) along with serum samples of patients were collected. Control for the serum samples is from the patients undergoing simple nephrectomy for non-functioning kidney due to benign etiology. The GRP78 expression was studied using RT-PCR for mRNA expression, Western blot analysis and immunohistochemistry (IHC) for protein expression and using ELISA in serum for both the subjects and controls. RESULTS: Mean age of patients was 50.3 years. The mRNA and protein expression of GRP78 in tissue samples were significantly higher in RCC patients as compared to controls (p < 0.001). IHC also demonstrated significantly higher expression in tumour samples as compared to controls (p < 0.001). Circulatory levels of GRP78 in serum samples were also significantly increased (p < 0.0001) in RCC patients in comparison to control subjects. The expression of GRP78 in circulation significantly correlated with the pathological tumor stage (p = 0.03), grade of disease (p < 0.001). CONCLUSION: The GRP78 in RCC is significantly upregulated both at molecular and protein level expression. The overexpression of GRP78 correlates with the stage and grade of disease, thereby, highlighting its prognostic ability.

22(R)-hydroxycholesterol for dopaminergic neuronal specification of MSCs and amelioration of Parkinsonian symptoms in rats.

Oxysterols play vital roles in the human body, ranging from cell cycle regulation and progression to dopaminergic neurogenesis. While naïve human mesenchymal stem cells (hMSCs) have been explored to have neurogenic effect, there is still a grey area to explore their regenerative potential after in vitro differentiation. Hence, in the current study, we have investigated the neurogenic effect of 22(R)-hydroxycholesterol (22-HC) on hMSCs obtained from bone marrow, adipose tissue and dental pulp. Morphological and morphometric analysis revealed physical differentiation of stem cells into neuronal cells. Detailed characterization of differentiated cells affirmed generation of neuronal cells in culture. The percentage of generation of non-DA cells in the culture confirmed selective neurogenic potential of 22-HC. We substantiated the efficacy of these cells in neuro-regeneration by transplanting them into Parkinson's disease Wistar rat model. MSCs from dental pulp had maximal regenerative effect (with 80.20 ± 1.5% in vitro differentiation efficiency) upon transplantation, as shown by various behavioural examinations and immunohistochemical tests. Subsequential analysis revealed that 22-HC yields a higher percentage of functional DA neurons and has differential effect on various tissue-specific primary human MSCs. 22-HC may be used for treating Parkinson's disease in future with stem cells.

Positional preferences in flavonoids for inhibition of ribonuclease A: Where "OH" where?

Flavonoids are a class of polyphenols that possess diverse properties. The structure-activity relationship of certain flavonoids and resveratrol with ribonuclease A (RNase A) has been investigated. The selected flavonoids have a similar skeleton and the positional preferences of the phenolic moieties toward inhibition of the catalytic activity of RNase A have been studied. The results obtained for RNase A inhibition by flavonoids suggest that the planarity of the molecules is necessary for effective inhibitory potency. Agarose gel electrophoresis and precipitation assay experiments along with kinetic studies reveal Ki values for the various flavonoids in the micromolar range. Minor secondary structural changes of RNase A were observed after interaction with the flavonoids. An insight into the specific amino acid involvement in the binding of the substrate using docking studies is also presented. The dipole moment of the flavonoids that depends on the orientation of the hydroxyl groups in the molecule bears direct correlation with the inhibitory potency against RNase A. The direct association of this molecular property with enzyme inhibition can be exploited for the design and development of inhibitors of proteins.

Gelatin-polycaprolactone-nanohydroxyapatite electrospun nanocomposite scaffold for bone tissue engineering.

Bone injuries and fractures generally take a long period to heal itself. To address this problem, bone tissue engineering (BTE) has gained significant research impetus. Among the several techniques used for scaffold fabrication, electrospinning ought to be the most promising technique for the development of the nanostructured scaffolds. The present study was carried out to fabricate an electrospun nanocomposite scaffold for BTE by using gelatin, polycaprolactone (PCL), and nanohydroxyapatite (nHAp). To prepare Gelatin-PCL-nHAp nanocomposite scaffold: Gelatin-PCL blend was electrospun and then treated with nHAp (1 wt%) for different time periods. The fabricated nanocomposite scaffold was analysed by field emission scanning electron microscopy (FESEM) to determine the fiber diameter and evaluate the fiber morphology. The Gelatin-PCL-nHAp nanocomposite scaffold-20 min exhibited the average fiber diameter of 615±269 nm and average pore size 4.7±1.04 µm, and also revealed the presence of nHAp particles over the Gelatin-PCL scaffold surface. Further, X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy and thermogravimetric (TG) analysis also indicated the deposition of nHAp over the Gelatin-PCL scaffold surface. MTT assay and DNA quantification showed good viability and significant proliferation of human osteoblasts on Gelatin-PCL-nHAp nanocomposite scaffold. Moreover, cell-scaffold constructs illustrated efficient cellular attachment and adequately spread cells, and it also depicts characteristic polygonal morphology of osteoblasts over the Gelatin-PCL-nHAp nanocomposite scaffold. Thus, the results of in-vitro analysis of electrospun nanocomposite scaffold suggest that the Gelatin-PCL-nHAp scaffold can be a potential candidate for BTE applications.

Evaluation of the Graft Kidney in the Early Postoperative Period: Performance of Contrast-Enhanced Ultrasound and Additional Ultrasound Parameters.

OBJECTIVES: To evaluate the various quantitative parameters of Doppler ultrasound, contrast-enhanced ultrasound (CEUS), and shear wave elastography (SWE) of graft kidneys in the early postoperative period and to explore their utility in the diagnosis of parenchymal causes of graft dysfunction. METHODS: In this ethically approved study, consecutive patients who underwent renal transplantation from March 2017 to August 2018 were recruited, and those with urologic or vascular complications and those who denied consent were excluded. All patients underwent ultrasound with Doppler, SWE, CEUS (using sulfur hexafluoride), and renal scintigraphic examinations 3 to 10 days after transplantation. A composite reference standard was used, including the clinical course, renal function test results, urine output, and histopathologic results for graft dysfunction. Cortical SWE values, quantitative CEUS parameters (generated from a time-intensity curve), and their ratios were analyzed to identify graft dysfunction and differentiate acute tubular necrosis (ATN) from acute rejection (AR). RESULTS: Of the 105 patients included, 19 developed graft dysfunction (18.1%; 12 ATN, 5 AR, and 2 drug toxicity) in the early postoperative period. The peak systolic velocity in the interpolar artery showed a significant difference between control and graft dysfunction groups (P < .001) as well as between ATN and AR (P = .019). Resistive indices and SWE did not show significant differences. Ratios of the time to peak showed a significant difference between control and graft dysfunction groups (P < .05). The rise time and fall time of the large subcapsular region of interest and the rise time ratio were significantly different between ATN and AR (P = .03). CONCLUSIONS: Contrast-enhanced ultrasound can be used to diagnose parenchymal causes of early graft dysfunction with reasonable diagnostic accuracy.

Emerging Role of Elastin-Like Polypeptides in Regenerative Medicine.

Significance: Wound dressing based on naturally derived polymer provides a useful platform for treatment of skin injuries. Owing to the high mechanical strength and tunable structural and physicochemical properties of human elastin-like polypeptides (ELPs), they may be used as excellent materials for fabricating biocompatible scaffolds and other products for wound management. Recent Advances: Designing recombinant ELPs mimicking natural elastin to fabricate synthetic polymers suitable for human health care has generated significant interest. ELP-based cell-adhesive biopolymers have been used as an alternative for successful sutureless wound closure due to the physicochemical characteristics of the extracellular matrix. Critical Issues: Different systems of ELPs are being developed in the form of scaffolds, films, hydrogels, photo-linkable sheets, and composites linked with various types of growth factors for wound healing application. However, optimizing the quality and safety attributes for specific application needs designing of recombinant ELPs with structural and functional modifications as needed for the intervention. Future Direction: Chronic wounds are difficult to treat as the wound repair process is interrupted by conditions such as excessive inflammation, impaired extracellular matrix formation, and persistent infections. Conventional therapies such as skin substitutes or autologous skin grafts, in many cases, are unable to reestablish tissue homeostasis and proper healing. The development of innovative materials could induce a better regenerative healing response. In this study, we are reviewing different types of elastin-based materials for wound care application and their future prospects in regenerative medicine.

Mesenchymal Stem Cell Derived Exosomes: a Nano Platform for Therapeutics and Drug Delivery in Combating COVID-19.

The recent pandemic situation transpired due to coronavirus novel strain SARS-CoV-2 has become a global concern. This human coronavirus (HCov-19) has put the world on high alert as the numbers of confirmed cases are continuously increasing. The world is now fighting against this deadly virus and is leaving no stone unturned to find effective treatments through testing of various available drugs, including those effective against flu, malaria, etc. With an urgent need for the development of potential strategies, two recent studies from China using Mesenchymal Stem Cells (MSCs) to treat COVID-19 pneumonia have shed some light on a potential cure for the COVID-19 infected patients. However, MSCs, despite being used in various other clinical trials have always been questioned for their tendency to aggregate or form clumps in the injured or disease microenvironment. It has also been reported in various studies that exosomes secreted by these MSCs, contribute towards the cell's biological and therapeutic efficacy. There have been reports evaluating the safety and feasibility of these exosomes in various lung diseases, thereby proposing them as a cell-free therapeutic agent. Also, attractive features like cell targeting, low-immunogenicity, safety, and high biocompatibility distinguish these exosomes from other synthetic nano-vesicles and thus potentiate their role as a drug delivery nano-platform. Building upon these observations, herein, efforts are made to give an overview of stem cell-derived exosomes as an appealing therapeutic agent and drug delivery nano-carrier. In this review, we briefly recapitulate the recent evidence and developments in understanding exosomes as a promising candidate for novel nano-intervention in the current pandemic scenario. Furthermore, this review will highlight and discuss mechanistic role of exosomes to combat severe lung pathological conditions. We have also attempted to dwell into the nano-formulation of exosomes for its better applicability, storage, and stability thereby conferring them as off the shelf therapeutic.