Protein Paper from Exfoliated Eri Silk Nanofibers.

The exfoliation of silk fiber is an attractive method to produce silk micro- and nanofibers that retain the secondary structure of native silk. However, most fibrillation methods used to date require the use of toxic and/or expensive solvents and the use of high energy. This study describes a low cost, scalable method to produce microfibrillated silk nanofibers without the use of toxic chemicals by controlling the application of shear using commercially scalable milling and homogenization equipment. Manipulation of the degumming conditions (alkaline concentration and degumming temperature) and the shear in milling and/or homogenization enabled control over the degree of fibrillation. The microfibrillated silk was then characterized to determine structural change during processing and the stability of the resulting suspensions at different pH. Silk nanofibers obtained from milling degummed silk were characterized using atomic force microscopy. Nanofibers obtained both with and without high-pressure homogenization were then used to produce silk "protein paper" through casting. Silk degumming conditions played a critical role in determining the degree of microfibrillation and the properties of the cast silk papers. The silk papers produced from homogenized nanofibers showed excellent mechanical properties, high water absorption, and wicking properties. The silk papers were excellent for supporting the attachment and growth of human skin keratinocytes, demonstrating application possibilities in healthcare such as wound healing.

Biomaterials for topical and transdermal drug delivery in reconstructive transplantation.

Lifelong systemic immunosuppression remains the biggest challenge in vascularized composite allotransplantation (VCA) due to the adverse effects it causes. Since VCA is a life-enhancing procedure as compared with solid organ transplant which is life-saving; one needs to weigh the benefits and risks carefully. Thus, there is a huge unmet clinical need to design biomaterial-based vehicles that can deliver drugs more efficiently, topically and locally to eliminate adverse effects of systemic immune suppression. This review discusses several biomaterial-based systems that have been carefully designed, conceived and attempted to make VCA a more patient compliant approach. Variety of promising preclinical studies has shown the feasibility of the approaches, and clinical trials are required to bridge the gap. Several challenges for the future and new approaches have been discussed.

Silk particles, microfibres and nanofibres: A comparative study of their functions in 3D printing hydrogel scaffolds.

Silk, with highly crystalline structure and well-documented biocompatibility, is promising to be used as reinforcing material and build functionalized composite scaffolds. In the present study, we developed chitosan/silk composite scaffolds using silk particles, silk microfibres and nanofibres via 3D printing method. The three forms of silk fillers with varied shapes and dimensions were obtained via different processing methods and evaluated of their morphology, crystalline structure and thermal property. All silk fillers showed different degrees of improvement on printability in terms of ink rheology and printing shape fidelity. Different silk fillers led to different scaffold surface morphology and different roughness, while all reduced the contact angle compared to pure chitosan. Similar reinforcements were observed on compressive modulus, while oscillatory gel strength reinforcement was found to be positively correlated to the filler aspect ratio. Addition of silk introduced no cytotoxicity for that all scaffolds supported a steady cell growth using human fibroblasts. Meanwhile different cellular behaviours were observed on different scaffold surfaces, which can possibly intriguer specific application on soft tissue engineering.

Iron-Copper Bimetallic Nanocomposite Reinforced Dressing Materials for Infection Control and Healing of Diabetic Wound.

A multifunctional nanomaterial based wound healing matrix was fabricated by modified co-precipitation and chemical reduction method. The matrix was comprised of either a bimetallic Fe-Cu nanocomposite powder or a wound bed made up of absorbent cotton swab impregnated with bimetallic Fe-Cu nanocomposite. The detailed analytical studies of both dressing materials (powder and cotton bed) were carried out with transmission electron microscopy, X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray, and bright field microscopy. Both the nanocomposite powder and the nanocomposite impregnated cotton swab exhibited antimicrobial activity against Gram positive and Gram negative bacteria, including multidrug-resistant bacteria (such as methicillin-resistant Staphylococcus aureus) as well as against fungus isolated from different human biological samples (pus/tissue culture/urine). For real time applications, the in vivo wound healing ability of both dressing materials was also carried out in Wistar albino rats with infected diabetic wounds. These biocompatible and biodegradable dressing materials with broad-spectrum antimicrobial properties have exhibited more than 20 mm in diameter zone of microbial growth inhibition against several types of microbes. Remarkably, they have also been found to assist in healing of infected diabetic wounds and show a prospect in the management of other infectious wounds.

Polyethylene Glycol-Encapsulated Histone Deacetylase Inhibitor Drug-Composite Nanoparticles for Combination Therapy with Artesunate.

Combination drug therapy has become an effective clinical practice for cancer treatment because of low cytotoxicity by the synergistic effect of each medicine. Luminescent Au nanoclusters (Au NCs) were formulated into spherical polyethylene glycol (PEG)-Au NC-encapsulated drug-sodium butyrate (NaB) composite nanoparticles (PEG-Au NC-NaB-NPs) in the presence of PEG and NaB. Their effect on cancer cells was investigated using bio imaging, unravelling the mechanism of the endocytosis pathway and combination therapeutic interventions with a plant-based antimalarial drug artesunate (ART). PEG-Au NC-NaB-NPs showed bright red luminescence in the lysosomal compartment of the cells upon uptake predominantly through a caveolae-mediated pathway. Combination of PEG-Au NC-NaB-NPs with ART displayed enhanced therapeutic activity at a reduced dose compared to its individual doses and revealed heightened synergistic activity as identified from the combination index. The mechanism of synergism revealed elevated generation of reactive oxygen species with both NaB and ART, which disrupts mitochondrial membrane potential as evident from JC-1 staining. Remarkably, the histone deacetylase (HDAC) assay and terminal deoxynucleotidyl transferase dUTP nick end labeling assay enlightened the role of NaB and ART in HDAC inhibition and DNA fragmentation, respectively. Thus, induction of apoptosis with the synergistic effect of both NaB and ART with its meticulous mechanism makes it a promising tool for combinational cancer therapy. In vivo activity of the NPs was evaluated on Daltons lymphoma ascites bearing mice, which exhibited significant reduction of tumor volume and viable tumor cells with a prolonged life span.

Functionalization of ß-lactam antibiotic on lysozyme capped gold nanoclusters retrogress MRSA and its persisters following awakening.

In this study we have reported an efficient antibacterial hybrid fabricated through surface functionalization of lysozyme capped gold nanoclusters (AUNC-L) with ß-lactam antibiotic ampicillin (AUNC-L-Amp). The prepared hybrid not only reverted the MRSA resistance towards ampicillin but also demonstrated enhanced antibacterial activity against non-resistant bacterial strains. Most importantly, upon awakening through cis-2-decenoic acid (cis-DA) exposure, the MRSA persister got inhibited by the AUNC-L-Amp treatment. Intraperitoneal administration of this hybrid eliminates the systemic MRSA infection in a murine animal model. Topical application of this nano conjugate eradicated MRSA infection from difficult to treat diabetic wound of rat and accelerated the healing process. Due to inherent bio-safe nature of gold, AUNC-L alone or in the construct (AUNC-L-Amp) demonstrated excellent biocompatibility and did not indicate any deleterious effects in in vivo settings. We postulate that AUNC-L-Amp overcomes the elevated levels of ß-lactamase at the site of MRSA antibiotic interaction with subsequent multivalent binding to the bacterial surface and enhanced permeation. Coordinated action of AUNC-L-Amp components precludes MRSA to attain resistance against the hybrid. We proposed that the inhibitory effect of AUNC-L-Amp against MRSA and its persister form is due to increased Amp concentration at the site of action, multivalent presentation and enhanced permeation of Amp through lysozyme-mediated cell wall lysis.

Transferrin-Copper Nanocluster-Doxorubicin Nanoparticles as Targeted Theranostic Cancer Nanodrug.

Transferrin (Tf)-templated luminescent blue copper nanoclusters (Tf-Cu NCs) are synthesized. They are further formulated into spherical Tf-Cu NC-doxorubicin nanoparticles (Tf-Cu NC-Dox NPs) based on electrostatic interaction with doxorubicin (Dox). The as-synthesized Tf-Cu NC-Dox NPs are explored for bioimaging and targeted drug delivery to delineate high therapeutic efficacy. Förster resonance energy transfer (FRET) within the Tf-Cu NC-Dox NPs exhibited striking red luminescence, wherein the blue luminescence of Tf-Cu NCs (donor) is quenched due to absorption by Dox (acceptor). Interestingly, blue luminescence of Tf-Cu NCs is restored in the cytoplasm of cancer cells upon internalization of the NPs through overexpressed transferrin receptor (TfR) present on the cell surface. Finally, gradual release of Dox from the NPs leads to the generation of its red luminescence inside the nucleus. The biocompatible Tf-Cu NC-Dox NPs displayed superior targeting efficiency on TfR overexpressed cells (HeLa and MCF-7) as compared to the cells expressing less TfR (HEK-293 and 3T3-L1). Combination index (CI) revealed synergistic activity of Tf-Cu NCs and Dox in Tf-Cu NC-Dox NPs. In vivo assessment of the NPs on TfR positive Daltons lymphoma ascites (DLA) bearing mice revealed significant inhibition of tumor growth rendering prolonged survival of the mice.

Development of banana (Musa balbisiana) pseudo stem fiber as a surgical bio-tool to avert post-operative wound infections.

The search to develop an ideal suture material encourages us to explore novel suture biomaterials with superior characteristics to the current commercially available products. Surgical sutures play a crucial role in the development of post-operative wound infection by acting as a substrate for biofilm formation which leads to dehisced wounds. In this context, the present invention meets this need by fabricating banana (Musa balbisiana) fibre into an advanced antimicrobials releasing suture biomaterial (BSc) for the prevention of post-operative wound infection. Suture material developed from banana pseudo stem fiber was impregnated with chloramphenicol, clotrimazole and growth factors with the aid of a hydro-gel system. The fabricated suture material was found to be biocompatible towards human erythrocytes and L929 mouse fibroblast cells. BSc exhibited promising physico-chemical characteristics which were comparable to the commercially available Bombyx mori silk fibroin (BMSF) suture. BSc displayed a biphasic release pattern with sustained release of chloramphenicol for up to 140 h. Apart from being environment friendly and having a facile fabrication method, this advanced suture biomaterial showed broad spectrum in vitro antimicrobial activity against bacterial and fungal pathogens. BSc successfully impeded biofilm formation on its surface, as is evident from the confocal microscopy analysis. This contributes to superior wound healing efficacy in terms of reduced microbial burden and a subsequent decrease in the inflammatory cytokine levels. Histopathological observations further supported the pronounced healing efficacy of BSc sutured wounds. The findings of this study establish the banana pseudo stem fiber as a novel advanced suture biomaterial to prevent post-operative wound infections.

Glycogen-gold nanohybrid escalates the potency of silymarin.

In this study, a glycogen-gold nanohybrid was fabricated to enhance the potency of a promising hepatoprotective agent silymarin (Sly) by improving its solubility and gut permeation. By utilizing a facile green chemistry approach, biogenic gold nanoparticles were synthesized from Annona reticulata leaf phytoconstituents in combination with Sly (SGNPs). Further, the SGNPs were aggregated in glycogen biopolymer to yield the therapeutic nanohybrids (GSGNPs). Transmission electron microscopy, UV-Vis spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy analysis confirmed the successful formation and conjugation of both SGNPs and GSGNPs. The fabricated nanohybrids showed significant protection against CCl4-induced hepatic injury in Wistar rats and maintained natural antioxidant (superoxide dismutase and catalase) levels. Animals treated with GSGNPs (10 mg/kg) and SGNPs (20 mg/kg) retained usual hepatic functions with routine levels of hepatobiliary enzymes (aspartate transferase, alanine transaminase, alkaline phosphatase, and lactate dehydrogenase) and inflammatory markers (interleukin-1ß and tumor necrosis factor-α) with minimal lipid peroxidation, whereas those treated with 100 mg/kg of Sly showed the similar effect. These results were also supported by histopathology of the livers where pronounced hepatoprotection with normal hepatic physiology and negligible inflammatory infiltrate were observed. Significant higher plasma Cmax supported the enhanced bioavailability of Sly upon GSGNPs treatment compared to SGNPs and free Sly. Graphite furnace atomic absorption spectrophotometry analysis also substantiated the efficient delivery of GSGNPs over SGNPs. The fabricated therapeutic nanohybrids were also found to be biocompatible toward human erythrocytes and L929 mouse fibroblast cells. Overall, due to increased solubility, bioavailability and profuse gut absorption; GSGNPs demonstrated tenfold enhanced potency compared to free Sly.

Bioactive Fraction of Annona reticulata Bark (or) Ziziphus jujuba Root Bark along with Insulin Attenuates Painful Diabetic Neuropathy through Inhibiting NF-κB Inflammatory Cascade.

The present study explains the neuroprotective ability of bioactive fractions of Annona reticulata bark (ARB) and Ziziphus jujuba root bark (ZJ) along with insulin against diabetic neuropathy. By using different solvents of increasing polarity ARB and ZJ were undergone for bioactive guided fractionation. The neuroprotective ability of the all the plant fractions were tested against H2O2 induced toxicity in SHSY5Y neuroblastoma cell lines and DRG neuronal cells. Among all the fractions tested, the methanol extract of ARB and ZJ (ARBME and ZJME) and its water fractions (ARBWF and ZJWF) exhibited significant neuroprotection against H2O2 induced toxicity in SHSY5Y cells and DRG neuronal cells. Further both the active fractions were tested against streptozotocin (55 mg/kg i.p.) induced diabetic neuropathy in male Wistar rats. Body weight changes, blood glucose levels and pain threshold through hot plate, tail immersion, cold plate and Randall-Sillitto methods were measured throughout the study at weekly interval. After completion of the drug treatment period, all the animals were sacrificed to measure the sciatic nerve lipid peroxidation, antioxidative enzyme levels (SOD, catalase, and GSH) and cytokine levels (IL-1ß, IL-6, IL-10, TNF-α, iNOS, and NFκB) through ELISA and western blotting analysis. Results of this study explain that ARBME, ZJME, ARBWF, and ZJWF along with insulin potentially attenuate the thermal, mechanical hyperalgesia and cold allodynia in diabetic neuropathic rats, where insulin treatment alone failed to diminish the same. Reduction of sciatic nerve oxidative stress, NF-κB and iNOS mediated inflammatory cascade and normalization of abnormal cytokine release confirms the possible mechanism of action. The present study confirms the neuroprotective ability of ARB and ZJ against painful diabetic neuropathy through inhibiting oxidative stress and NF-κB inflammatory cascade.

Protective Effect of Bioactivity Guided Fractions of Ziziphus jujuba Mill. Root Bark against Hepatic Injury and Chronic Inflammation via Inhibiting Inflammatory Markers and Oxidative Stress.

The tribal communities of North Eastern India rely on herbal medicine to cure various disease conditions. Ziziphus jujuba Mill. (Rhamnaceae) is one of such medicinal plants used for curing liver ailments, insomnia, anemia, diarrhea, diabetic complications, cancer, and loss of appetite. The present study was aimed to describe the protective ability of Z. jujuba root bark (ZJRB) against hepatic injury and chronic inflammation. Bioactivity guided fractionation of Z. jujuba methanol extract (ZJME) was performed using different solvents of increasing polarity viz. hexane (ZJHF), chloroform (ZJCF), ethyl acetate (ZJEAF), water (ZJWF), and residue (ZJMR). In vitro antioxidant results revealed that both ZJME and ZJWF possess strong antioxidant activity among all the fractions and mother extract tested. Further, ZJME and ZJWF showed significant protection against CCl4 intoxicated HepG2 cell lines by means of increased cell viability and decreased LDH levels compared to control group. ZJME at 200, 400 mg/kg and ZJWF at 50, 100 mg/kg inhibited the lipid peroxidation and significantly restored the liver function markers (AST, ALT, ALP, LDH, SOD, and CAT) and cytokine levels (TNF-α, Il-1ß, and Il-10) in CCl4 induced acute liver damage in rats. All the results were comparable with standard drug silymarin which was further confirmed by histopathology analysis of liver. Similarly, inflammation and increase inflammatory cytokines levels of carrageenan induced paw edema in rats have been refurbished to normal levels on par with the standard drug indomethacin. ZJWF demonstrated potent response than ZJME in all the biological tests conducted. The results of the study signify the ability of ZJRB as good therapeutic agent for liver toxicity and chronic inflammation.

Chitosan-Iron Oxide Coated Graphene Oxide Nanocomposite Hydrogel: A Robust and Soft Antimicrobial Biofilm.

We report a robust biofilm with antimicrobial properties fabricated from chitosan-iron oxide coated graphene oxide nanocomposite hydrogel. For the first time, the coprecipitation method was used for the successful synthesis of iron oxide coated graphene oxide (GIO) nanomaterial. After this, films were fabricated by the gel-casting technique aided by the self-healing ability of the chitosan hydrogel network system. Both the nanomaterial and the nanocomposite films were characterized by techniques such as scanning electron microscopy, FT-IR spectroscopy, X-ray diffraction, and vibrating sample magnetometry. Measurements of the thermodynamic stability and mechanical properties of the films indictaed a significant improvement in their thermal and mechanical properties. Moreover, the stress-strain profile indicated the tough nature of the nanocomposite hydrogel films. These improvements, therefore, indicated an effective interaction and good compatibility of the GIO nanomaterial with the chitosan hydrogel matrix. In addition, it was also possible to fabricate films with tunable surface properties such as hydrophobicity simply by varying the loading percentage of GIO nanomaterial in the hydrogel matrix. Fascinatingly, the chitosan-iron oxide coated graphene oxide nanocomposite hydrogel films displayed significant antimicrobial activities against both Gram-positive and Gram-negative bacterial strains, such as methicillin-resistant Staphylococcus aureus, Staphylococcus aureus, and Escherichia coli, and also against the opportunistic dermatophyte Candida albicans. The antimicrobial activities of the films were tested by agar diffusion assay and antimicrobial testing based on direct contact. A comparison of the antimicrobial activity of the chitosan-GIO nanocomposite hydrogel films with those of individual chitosan-graphene oxide and chitosan-iron oxide nanocomposite films demonstrated a higher antimicrobial activity for the former in both types of tests. In vitro hemolysis potentiality tests and MTT assays of the nanocomposite films indicated a noncytotoxic nature of the films, which conveyed the possibility of potential applications of these soft and tough films in biomedical as well as in the food industry.

Bioactive Guided Fractions of Annona reticulata L. bark: Protection against Liver Toxicity and Inflammation through Inhibiting Oxidative Stress and Proinflammatory Cytokines.

Herbal medicine is popularized worldwide due to its ability to cure the diseases with lesser or no side effects. North Eastern part of India comes under one of the world biodiversity hotspots which is very rich in traditional herbal medicine. Annona reticulata L. (Annonaceae) is one such plant used for the treatment of inflammatory diseases, liver ailments and diabetes by traditional healers. The present study was aimed to scientifically validate this folk knowledge and to develop an herbal remedy through evaluating bioactive guided fractions of A. reticulata (AR) bark against hepatotoxicity and inflammation using in vitro and in vivo models. Results of this study demonstrates that among all fractions of AR bark, methanol extract and its water fraction possess strong anti-oxidant ability and showed protection against CCl4 induced toxicity in HepG2 cell lines and rats. Both the fractions also exhibit dose dependent anti-inflammatory activity against carrageenan induced inflammation in rats. Water fraction showed potent response in the entire tests conducted than methanol extract, which states that polar components of the AR bark methanol extract were responsible for these activities. Further, from the experiments conducted to elucidate the mechanism of action, the results revealed that AR bark showed liver protection and anti-inflammatory response through inhibiting the oxidative stress and inflammatory cytokines.

Chemical Composition and Anti-Candidiasis Mediated Wound Healing Property of Cymbopogon nardus Essential Oil on Chronic Diabetic Wounds.

Poor wound healing is one of the major complication of diabetic patients which arises due to different factors like hyperglycemia, oxidative stress, vascular insufficiency and microbial infections. Candidiasis of diabetic wounds is a difficult to treat condition and potentially can lead to organ amputation. There are a few number of medications available in market to treat this chronic condition; which demands for alternative treatment options. In traditional system of medicine like Ayurveda, essential oil extracted from leaves of Cymbopogon nardus L. (Poaceae) has been using for the treatment of microbial infections, inflammation and pain. In this regard, we have evaluated anti-Candida and anti-inflammatory activity mediated wound healing property of C. nardus essential oil (EO-CN) on candidiasis of diabetic wounds. EO-CN was obtained through hydro-distillation and subjected to Gas chromatography-mass spectroscopy (GC-MS) analysis for chemical profiling. Anti-Candida activity of EO-CN was tested against Candida albicans, C. glabrata and C. tropicalis by in vitro zone of inhibition and minimum inhibitory concentration (MIC) assays. Anti-candidiasis ability of EO-CN was evaluated on C. albicans infected diabetic wounds of mice through measuring candida load on the 7th, 14th, and 21st day of treatment. Further progression in wound healing was confirmed by measuring the inflammatory marker levels and histopathology of wounded tissues on last day of EO-CN treatment. A total of 95 compounds were identified through GC-MS analysis, with major compounds like citral, 2,6-octadienal-, 3,7-dimethyl-, geranyl acetate, citronellal, geraniol, and citronellol. In vitro test results demonstrated strong anti-Candida activity of EO-CN with a MIC value of 25 µg/ml against C. albicans, 50 µg/ml against C. glabrata and C. tropicalis. EO-CN treatment resulted in significant reduction of candida load on diabetic wounds. Acceleration in wound healing was indicated by declined levels of inflammatory cytokines at wounded area in EO-CN treated animals compared to non-treated group, which was further confirmed by histopathological examination. This study suggests that through significant anti-Candida and anti-inflammatory activity, EO-CN attenuates the growth of the fungus on diabetic wounds and simultaneously reduces the inflammation which leads to acceleration of the wound healing process.

Antioxidant and Hepatoprotective Potentiality of Randia dumetorum Lam. Leaf and Bark via Inhibition of Oxidative Stress and Inflammatory Cytokines.

Randia dumetorum Lam. (RD) (Rubiaceae) is traditionally used by some tribes of Assam and Manipur of North East India for the treatment of liver ailments. In this context, to scientifically validate this indigenous traditional knowledge, we have evaluated the antioxidant and hepatoprotective activity of RD leaf and bark. The methanol extracts of RD leaf and bark were evaluated for in vitro antioxidant activity which exhibited good antioxidant activity in terms of reducing power assay, total antioxidant assay and DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging assay. Total phenolic and flavonoid content were found to be 112 ± 3.24 mg and 138 ± 2.46 mg gallic acid equivalents/g extract and 2.6 ± 0.26 mg and 3.34 ± 0.31 mg rutin equivalents/g extract respectively for RD leaf and bark methanol extracts. The in vivo hepato protective activity of the RD leaf and bark extract was evaluated against carbon tetrachloride (CCl4) induced hepatic damage in male wistar rats. CCl4 administration induced hepatic damage in rats resulted in increased levels of aspartate transaminase, alanine transaminase, alkaline phosphatase, lactate dehydrogenase, thiobarbituric acid reacting substances, albumin, bilirubin, TNF-α, IL-1ß and decreased levels of total protein and antioxidant enzymes like superoxide dismutase, catalase, and glutathione reductase. RD leaf and bark methanol extracts pre-treatment exhibited protection against CCl4 induced hepatotoxicity by reversing all the abnormal parameters to significant levels. Histopathological results revealed that RD leaf and bark extracts at 400 mg/kg protects the liver from damage induced by CCl4. The results of this study scientifically validate the traditional use of RD leaf and bark for the treatment of liver ailments.

Fiber from ramie plant (Boehmeria nivea): A novel suture biomaterial.

The quest for developing an ideal suture material prompted our interest to develop a novel suture with advantageous characters to market available ones. From natural origin only silk, cotton and linen fibers are presently available in market as non-absorbable suture biomaterials. In this study, we have developed a novel, cost-effective, and biocompatible suture biomaterial from ramie plant, Boehmeria nivea fiber. Field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and thermo gravimetric analysis (TGA) results revealed the physicochemical properties of raw and degummed ramie fiber, where the former one showed desirable characteristics for suture preparation. The braided multifilament ramie suture prepared from degummed fiber exhibited excellent tensile strength. The suture found to be biocompatible towards human erythrocytes and nontoxic to mammalian cells. The fabricated ramie suture exhibited significant antibacterial activity against Escherichia coli, Bacillus subtilis and Staphylococcus aureus; which can be attributed to the inherent bacteriostatic ability of ramie plant fiber. In vivo wound closure efficacy was evaluated in adult male wister rats by suturing the superficial wound incisions. Within seven days of surgery the wound got completely healed leaving no rash and scar. The role of the ramie suture in complete wound healing was supported by the reduced levels of serum inflammatory mediators. Histopathology studies confirmed the wound healing ability of ramie suture, as rapid synthesis of collagen, connective tissue and other skin adnexal structures were observed within seven days of surgery. Tensile properties, biocompatibility and wound closure efficacy of the ramie suture were comparable with market available BMSF suture. The outcome of this study can drive tremendous possibility for the utilization of ramie plant fiber for various biomedical applications.

Amoxicillin functionalized gold nanoparticles reverts MRSA resistance.

In this study, we have described the biosynthesis of biocompatible gold nanoparticles (GNPs) from aqueous extract of the aerial parts of a pteridophyte, "Adiantum philippense" by microwave irradiation and its surface functionalization with broad spectrum beta lactam antibiotic, amoxicillin (Amox). The functionalization of amoxicillin on GNPs (GNP-Amox) was carried out via electrostatic interaction of protonated amino group and thioether moiety mediated attractive forces. The synthesized GNPs and GNP-Amox were physicochemically characterized. UV-Vis spectroscopy, Zeta potential, XRD, FTIR and SERS (surface enhanced raman spectra) results confirmed the loading of Amox into GNPs. Loading of Amox to GNPs reduce amoxicillin cytotoxicity, whereas GNPs were found to be nontoxic to mouse fibroblast cell line (L929) as evident from MTT and acridine orange/ethidium bromide (AO/EtBr) live/dead cell assays. The GNP-Amox conjugates demonstrated enhanced broad-spectrum bactericidal activity against both Gram-positive and Gram-negative bacteria. Furthermore, in-vitro and in-vivo assays of GNP-Amox revealed potent anti-MRSA activity and improved the survival rate. This indicates the subversion of antibiotic resistance mechanism by overcoming the effect of high levels of ß-lactamase produced by methicillin resistant Staphylococcus aureus (MRSA). Taken together, this study demonstrates the positive attributes from GNP-Amox conjugates as a promising antibacterial therapeutic agent against MRSA as well as other pathogens.

Controlled antibiotic-releasing Antheraea assama silk fibroin suture for infection prevention and fast wound healing.

BACKGROUND: The quest for developing silk fibroin as a biomaterial for drug release systems continues to draw research interest owing to its impressive mechanical properties as well as biocompatibility and biodegradability. The aim of this study is to develop low-temperature O2 plasma-treated muga (Antheraea assama) silk fibroin (AASF) yarn impregnated with amoxicillin trihydrate as controlled antibiotic-releasing suture (AASF/O2/AMOX) for preventing postoperative site bacterial infection and fast wound healing. METHODS: In this experimental study, AASF and AASF/O2/AMOX sutures are used to close the surgical wounds of adult male Wistar rats of 4 months old and weighing 200-230 g. RESULTS: Surface hydrophilicity induced by O2 plasma results in an increase in drug-impregnation efficiency of AASF/O2 yarn by 16.7%. In vitro drug release profiles show continuous and prolonged release of AMOX from AASF/O2/AMOX yarn up to 336 hours. In vitro hemolysis assay reveals that O2 plasma treatment and subsequent impregnation of AMOX do not affect the heertetmocompatibility of AASF yarn. The AASF/O2/AMOX yarn proves to be effective for in vitro growth inhibition of Staphylococcus aureus and Escherichia coli, whereas AASF offers no antibacterial activity against both types of bacteria. In vivo histopathology studies and colony-forming unit count data revealed accelerated wound healing activity of AASF/O2/AMOX over AASF yarn through rapid synthesis and proliferation of collagen, hair follicle, and connective tissues. CONCLUSION: Outcomes of this work clearly demonstrate the potential use of AASF/O2/AMOX yarn as a controlled antibiotic-releasing suture biomaterial for superficial surgical applications.

Penicillin impregnation on oxygen plasma surface functionalized chitosan/Antheraea assama silk fibroin: Studies of antibacterial activity and antithrombogenic property.

Low temperature plasma can effectively tailor the surface properties of natural polymeric biomaterials according to the need for various biomedical applications. Non-mulberry silk, Antheraea assama silk fibroin (AASF) is a natural polymer having excellent biocompatibility and mechanical strength yet unlike mulberry silk, Bombyx mori silk fibroin, has drawn less interest in biomedical research. In the quest for developing as potential biomaterial, surface functionalization of plasma induced chitosan (Cs) grafted AASF ((AASF/O2-CS)g/O2) yarn is carried out using oxygen (O2) plasma. The (AASF/O2-CS)g/O2 yarn exhibits enhanced antithrombogenic property as well as antimicrobial activity against Gram positive (Bacillus subtilis) and Gram negative (Escherichia coli) bacteria as compared to AASF yarn. Moreover, impregnation of antibiotic drug (penicillin G sodium salt, PEN) on (AASF/O2-CS)g/O2 yarn further improves the observed properties. In-vitro hemolysis assay reveals that O2 plasma treatment and subsequent impregnation of PEN do not affect the hemocompatibility of AASF yarn. The present research findings demonstrate that plasma induced grafting of Cs followed by penicillin impregnation could significantly improve the potential applicability of AASF in the field of surgical research.