Polymeric Biomaterials and Bioengineering

Healing of the wound is one of the major burdens to diabetic patients and health care system. In the present study, the combination of silver nanoparticles and curcumin dispersed polyvinylpyrrolidone (PVP) nanofibrous bandage was developed for wound-healing applications. The silver nanoparticle was synthesized from green route using Phyllanthus Niruri extract as reducing agent and was identified by UV spectroscopy. The curcumin was extracted from Curcuma Longa L and was confirmed by UV spectroscopy. The synthesized silver nanoparticles and curcumin were incorporated into PVP solution and electrospun to develop nanofibrous bandage. The well-dispersed curcumin and silver nanoparticles in the PVP nanofibrous matrix were studied by transmission electron microscopy. The suitability and accessibility of the developed electrospun nanofibrous bandage for wound-healing application were tested by MTT assay using mouse embryonic fibroblast (NIH 3T3) cell lines and antibacterial activity using gram-positive and gram-negative bacteria. Hence, the developed electrospun bandage is the promising material for wound-healing applications due to its high surface area-to-volume ratio, interconnected porous nature and biomimics the extracellular matrix protein structure.

Bone scaffold is a three-dimensional matrix which stimulates the attachment and proliferation of osteoinducible cells on its surface. Use of scaffolds is the standard procedure to treat skeletal fractals, replace or regenerate the damaged/lost bone tissues. However, reproducing the complete features of the bone morphology, strength and porosity is a challenging task. The present study endeavors toward the preparation and bioactive studies of PCL/bioactive glass electrospun three-dimensional (3D) mat. The 3D mat was fabricated using eletrospinning process. To prepare biocomposites, 45S5 bioglass (1 wt%) prepared by sol–gel method was mixed with PCL (8 wt%) using chloroform and ethanol as a solvent, which has dispersibility and spinnability. The physicochemical characterization using X-ray diffraction and Fourier transform infrared spectroscopy confirmed the presence of bioglass in the biocomposite fibers. The scaffold structure was evaluated using scanning electron microscopy, which reveals the porous nature with an average fiber diameter of 116 ± 40 nm. In vitro studies revealed the mineralization ability of the prepared fibrous 3D mat in stimulated body fluid (SBF) under static conditions. The biocomposite scaffold exhibits higher calcium phosphate formation and higher degradation rate. These results indicate that PCL/BG biocomposite scaffolds as a favorable substance for bone tissue regeneration applications

Poly(methyl methacrylate) (PMMA) bone cement becomes a leading biomaterial in orthopedic applications due to its excellent biocompatibility and mechanical characteristics. While developing PMMA bone cement nanocomposite for enhanced performance in implant applications, machining property must be required. The drilling process is the most prevalent, particularly in the production of biomaterials and artificial implants. When utilizing PMMA bone cement to install bolts for safety and fixation, drilling on the prosthetic device(s) is usually considered necessary. Drilling on bone cement-based prosthetics has been the most utilized machining process during bone implants. Therefore, preference selection index (PSI) theory is employed in this article to investigate the effect of process factors on the drilling performance of hydroxyapatite (HA) modified PMMA bone cement bio-nanocomposites. The objective is to achieve the desired value of circularity error (C_er) and surface roughness (Sr) generated during the drilling process. Reinforcement (HA) weight percentage (Wt.%), speed of spindle (SPEED), and drill bit material (TOOL) such as TiAlN, carbide, and HSS are taken as varying parameters. Henceforth, the best setting was obtained using the PSI method as Wt.% = 10%, SPEED = 1428 rpm with the HSS drill bit tool. Predicted results have been verified by a confirmatory test that shows an improvement in responses using PSI results. With the help of the interaction plot, it was also found that at 10 wt. % value, both Sr and Cer show the optimum value, limiting the reinforcement of HA in PMMA bone cement for optimum machining performance.

Donepezil hydrochloride, an anticholinesterase drug, is orally administered to patients suffering from Alzheimer’s disease. Alzheimer’s is a neurodegenerative disorder characterized by the degradation of neurotransmitters, neuronal apoptosis, and loss of synapses. The treatment of such neural diseases is hampered by the presence of a tightly controlled blood–brain barrier (BBB), which prevents the influx of drugs. The intranasal route of drug delivery has been lately seen as a promising approach to deliver drugs directly to the brain, effectively bypassing the BBB, as it offers high absorption and increased bioavailability. In this study, we have fabricated hybrid polymeric lipid nanoparticles with two natural polymers—chitosan and gelatin. The average particle sizes of chitosan lecithin and gelatin lecithin nanoparticles were 237.43 and 278.86 nm. The percentage drug loading for chitosan lecithin and gelatin lecithin nanoparticles was 10.24 ± 0.4 and 8.77 ± 0.748%. The chitosan lecithin nanoparticles showed a burst release of up to 99.99% drug for 5 days, while the gelatin lecithin nanoparticles exhibited a sustained release of 33.31% drug for 30 days under acidic conditions. The cell viability studies showed that both nanoparticles were safe toward mouse fibroblast cells (L929). Finally, both nanoparticles were found to be mucoadhesive in nature. Out of the two nanoparticulate systems developed, the gelatin lecithin nanoparticles demonstrates a strong potential as a carrier for donepezil delivery.

Cognitive disorders (CDs) affect cognitive capabilities including memory, learning, perception and problem solving. Alzheimer’s disease is one of the most common cognitive disorders. Pullulan (a non-ionic polysaccharide) is a natural polymer having characteristic properties like non-toxicity, non-immunogenicity, biodegradability and high water solubility. Insulin signalling dysregulation and blood vessel disease in diabetes are the contributing factors for the pathogenesis of vascular dementia Alzheimer’s disease. One of the classes for oral anti-diabetic drugs is DPP-4 inhibitors and expressed on the surface of cell types that neutralizes GIP and GLP-1. In this work, we propose to use a natural polymer (pullulan) for the production of nanoformulations (polymeric nanomicelles) intended for improving absorption of dpp-4 inhibitor in cognitive disorder. Direct dissolution method is used for the preparation of DPP-4 loaded polymeric nanomicelles and characterized for particle shape, particle size, zeta potential, drug loading, entrapment efficiency and in vitro release. The best formulation showed mean particle diameter of 281.9 nm and zeta potential (-6.94 mV). The optimized formulation showed 83.78 ± 0.56% of release for 24 h in a controlled manner, when compared with plain drug with release for 16–18 h while performing the in vitro release studies. The release kinetics of optimized formulation showed the best followed model of Korsemeyer-Peppas. The in vivo activity was evaluated for optimized nanoformulation in mice by performing Morris Water Maze test. Optimized nanoformulation was found to be effective in mice model for behavioural studies. Thus, the pullulan-based nanoformulation showed remarkably better candidate for improved absorption and high bioavailability.

Cu(II)-catalyzed synthesis of low-molecular weight linear and hyperbranched polyesters at ambient temperature. Biodegradable polyesters are biohybrid materials, which have been widely used in various fields such as tissue engineering and regenerative medicines. Particularly, the low-molecular weight biodegradable polymers have received attention in medical applications as materials for molecular engineering. Controlled/living ring opening polymerization (ROP) of cyclic esters is the most efficient method for the synthesis of polyesters of desired molecular weight. Herein, we describe copper perchlorate hexahydrate (Cu(ClO₄)₂·6H₂O)-catalyzed synthesis of poly(ϵ-caprolactone) (PCL) and poly(δ-valerolactone) (PVL) under solvent-free conditions at room temperature, in the presence of benzyl alcohol, 1,5-pentandiol and propargyl alcohol as external initiators. In addition, star-shaped PCL and PVL have also been synthesized using pentaerythritol and dipentaerythritol initiators. The polyesters were characterized by ¹H NMR spectroscopy, gel permeation chromatography (GPC) and thermal analysis. Low-molecular weight polymers were obtained. The polymerization proceeds via an activated monomer mechanism.

Plastic and polythene waste collecting in the surroundings provide an ever-increasing environmental threat. This study examined on the biodegradation of polythene bags. However, low-density polyethylene (LDPE) is one of the few polymers that cannot be successfully decomposed. Microorganisms and enzymes proved to be the most effective polythene degraders. Enzymatic activity of microorganisms causes microbial degradation of polythene, resulting in chain breakage of the polymer into monomers. The purpose of this study is to investigate the characterisation, separation, and degradative ability of soil-based plastic-degrading microorganisms. Polythene was effectively broken down by bacteria isolated from waste soil samples. The polythene-degrading bacteria in the deposited soil are identified using biochemical assays and gram staining procedures. Bacillus sp., Arthobacter sp., and Pseudomonas sp. were shown to be efficient in the degradation of polythene bags in mineral salt media (MSM) in a weight determination method under laboratory conditions (in vitro) for 30 days. Polythene degradation was measured using the weight loss technique. According to the findings of this investigation, the Bacillus species is more effective for degrading plastic bags.

This study aims to synthesize and characterize crosslinked chitosan hydrogel and to utilize for adsorption of anionic azo dyes. The chitosan biopolymer was copolymerized with a vinyl monomer, acrylamide, and crosslinked with terephthalaldehyde via eco-friendly sonication route. The synthesized crosslinked hydrogel denoted as CAAmT was characterized using different techniques, viz. FTIR, TGA-DTG and SEM–EDX. The swelling studies of CAAmT were done at different pH which involves swelling kinetics also. The results of swelling kinetics revealed that CAAmT follows Fickian behavior. The CAAmT was applied for wastewater treatment focusing on adsorption of industrial dyes [cationic (malachite green and methylene blue) as well as anionic (congo red, solochrome dark blue, methyl orange, solochrome black and thymol blue)]. The results revealed that CAAmT was selective for anionic dyes and showed best results for congo red (CR) and solochrome dark blue (SDB). The percentage adsorption for CR and SDB was 96.2 and 92.1%, respectively. Further effect of all adsorption parameters, i.e., pH, adsorbent dosage, dye concentration, temperature, was evaluated for the adsorption of these two anionic azo dyes on CAAmT. The adsorption isotherms and kinetics were applied to adsorption of CR and SDB on CAAmT. The selectivity of CAAmT for anionic dyes was also checked in multicomponent system of dyes. The reusability studies of CAAmT were done to analyze the economic value of synthesized adsorbent.

Hydrogels have been developed for many years without any addition of traditional drugs. To speed up the wound-healing progress, banana sap was loaded into the hydrogel. The preparation of banana sap-loaded polyethylene glycol dimethacrylate/polyethylene oxide (PEGDMA/PEO) hydrogel film was done by adding the banana sap into PEGDMA/PEO solution before crosslinking using gamma rays. The composition of banana sap in hydrogel varies from 0 to 15% (by volume). The influence of banana sap on gel fraction, swelling ratio, water vapour transmission rate and mechanical properties of the hydrogel were measured after crosslinking. The surface morphology was investigated with scanning electron microscope (SEM). The increase in speed of wound-healing rate was tested by in vivo analysis. The research results showed that gel fraction, swelling ratio, water vapour transmission rate and elongation at break of banana-loaded PEGDMA/PEO hydrogel increase at various concentrations. On the contrary, tensile strength of hydrogel decreases with the increase of banana sap content. In vivo analysis indicates that hydrogel increases the speed of the wound healing. The results show that banana sap-loaded PEGDMA/PEO hydrogel is potential for wound-dressing applications.

In the present work, a new strategy for smart and auto-healing coatings is presented with improved mobility of healing agent. The findings presented here can tolerate damage at microscopic level more efficiently, thus showing improved corrosion resistance. Here, the improved self-healing efficiency of linseed oil which contains phenol-formaldehyde (PF) microcapsules was achieved with addition of less viscous soybean oil as a blend in various combinations. The PF microcapsules containing linseed oil (PF-LO) and soybean oil–linseed oil blends (PF-SLO) were synthesized successfully by in situ polymerization technique. A set of characterization method for synthesized microcapsules was used to confirm their morphology and chemical composition. The corrosion resistance of synthesized blended oil containing PF microcapsules incorporated coating specimens was compared with coating specimen of linseed oil-filled PF microcapsules (PF-LO).

Hydroxyapatite (HA) Ca₁₀(PO₄)₆(OH)₂ is the key mineral constituent of human hard tissue (70%) such as bone, dental enamel. Synthetic HA is a widely utilized component in dental as well as in non-load bearing implantation due to its excellent biocompatibility, inimitable bioactivity and stability. Diversified research works have been carried out to synthesize HA from various sources adopting different chemical methods so as to manage up with the bone response as a bioactive material. In this research work, HA powder was isolated from waste egg shells and clam shells using cost-effective method under controlled conditions. The characterization of synthesized HA powder from different sources is done using XRD, TGA, SEM and FTIR analysis. The formation of HA was confirmed by XRD and FTIR studies. TGA confirms the thermal stability of the sample. Morphology of the synthesized HA is obvious from SEM analysis. The use of egg shell and clam shell as HA precursors not only reduces the cost of bone repairing treatments, but also alleviates the environmental pollution due to the waste shells.

Alzheimer’s disease (AD) is a neurological disorder condition that results in the death of brain cells causing dementia, i.e., decline in cognitive functions. Despite extensive research on drug development, only a few drugs are approved by Food and Drug Administration (FDA) and available to manage AD progression. These synthetic drugs provide symptomatic relief despite adverse side effects, and hence, there remains an urgent need for identifying alternative therapeutic approaches to manage and cure AD. Several natural nootropics are reported to improve mental and cognitive functions via influencing different physiological pathways in the brain. The present article describes the rational selection and screening of five traditional ayurvedic herbs evaluating their neuroprotective activity using cell-based assays. The herbal extract-treated neuronal cells (SH-SY-5Y, neuroblastoma cell line) were exposed to 1-methyl-4-phenylpyridinium (MPP+ iodide), a neurotoxin that contains biologically inactive compound MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine), to evaluate the cytoprotecting ability of these herbs against MPP+ iodide. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay has been used to evaluate the percentage of cell restoration by herbal extracts after inducing damage by a toxic metabolite of the neurotoxin MPP+ (1 mM) in the cells. The results demonstrated that gotucola (100 μg/mL), brahmi (100 μg/mL), curcumin (100 μg/mL), tulsi (100 μg/mL) and rosemary (10 μg/mL) exhibited neuroprotective effects against AD, while the neuroprotective effect of brahmi was most significant. The results strongly indicate that natural herbal extracts possess the potential for therapeutic management of Alzheimer’s disease.

Formaldehyde is the most common indoor air contaminant (exposure limit of 30 min for 0.08 ppm has been set by WHO, World Health Organization) emitted from common building materials including wood furniture, carpets, plastic products, paints, varnishes. It is recently classified as carcinogenic and is associated with many other health risk factors such as respiratory disorders, nervous system damage that prompted the interest of scientific community in developing compact, simple, fast, and efficient gaseous formaldehyde room temperature detection materials. In the present work, MoS₂/RGO nanocomposites are developed as a hybridized 2D/2D functional nanocomposite chemiresistive sensing material for efficient formaldehyde detection. The MoS₂/RGO as 2D/2D nanocomposite sensing material addresses the challenges faced by existing flexible unary 2D sensing material such as selectivity, sensitivity, stability, response, and recovery time. The MoS₂/RGO nanocomposites are characterized through XRD and FTIR techniques. The electrical and sensing studies of synthesized material are evaluated through I–V characteristics using Keithley electrometer. Results revealed that the 2D/2D nanocomposites’ heterogeneous nature, high density of exposed active sites, heterojunction effect preventing charge accumulation during interaction with gas and catalytic properties of the individual constituents enhance the potential in terms of sensitivity, recovery, and response time of the sensing material.