Alginate templated synthesis, characterization and in vitro osteogenic evaluation of strontium-substituted hydroxyapatite.

The objective of this study is to explore the potential role of alginate (Alg) in the crystallization of metal-substituted hydroxyapatite, with application in orthopaedic reconstruction. The alginate at different concentrations (0.5 and 1.

Dextrose, maltose and starch guide crystallization of strontium-substituted hydroxyapatite: A comparative study for bone tissue engineering application.

The influence of carbohydrates on the crystallization of metal-substituted hydroxyapatite predicts its relevance to natural bone growth. This study demonstrates the role of carbohydrates in the crystallization of strontium-substituted hydroxyapatite (SHAP). The increasing order of hydroxyl groups, dextrose (monosaccharide) < maltose (disaccharide) < starch (polysaccharide), coordinated with Ca/Sr and thus guided SHAP crystallization, with crystal size reduced from 35 to 19 nm, lattice volume increased from 518 to 537 Å, and residual carbohydrates increased from 1.

Collagen Biocomposites Derived from Fish Waste: Doped and Cross-Linked with Functionalized FeO Nanoparticles and Their Comparative Studies with a Green Approach.

Collagen-based nanobiocomposites can reabsorb and are biodegradable. These properties are effectively controlled by the number of cross-links. This study demonstrates an effortless and proficient approach for the functionalization of FeO NPs for cross-linking collagen obtained from biowaste, viz.

Effect of pectin on the crystallization of strontium substituted HA for bone reconstruction application.

The biomacropolymers of bone extracellular matrix (ECM) guide the growth of hydroxyapatite (HA) with various ionic substitutions. Pectin, a plant polysaccharide with chemical similarities to ECM, was investigated for its potential to promote the crystallization of strontium-substituted HA (SH). The influence of pectin (0.

Development of a quaternary ammonium poly (amidoamine) dendrimer-based drug carrier for the solubility enhancement and sustained release of furosemide.

Furosemide (FRSD) is a loop diuretic that has been categorized as a class IV drug according to the Biopharmaceutics Classification System (BCS). It is used in the treatment of congestive heart failure and edema. Owing to low solubility and permeability, its oral bioavailability is very poor.

Graphene oxide reinforced SrHAP composite as a drug carrier in bone regeneration.

Strontium substituted HAP (SrHAP), with a 10 mol% substitution, was mineralized on increasing weight percentages of graphene oxide (2, 4 and 6). The GS composites were comprehensively characterized for drug delivery in bone reconstruction. The formation of SrHAP was verified by XRD and FT-IR results.

Evaluation of quaternization effect on chitosan-HAP composite for bone tissue engineering application.

This study attempts to improve the aqueous solubility of chitosan and utilizes it in the fabrication of composites with hydroxyapatite (HAP). The composites were evaluated as a curcumin delivery vehicle for bone regeneration. The chitosan was modified by quaternization, with a quaternization degree of 5 % for low quaternized chitosan (LQC) and 11 % for high quaternized chitosan (HQC).

Size controlled silver nanoparticles on β-cyclodextrin/graphitic carbon nitride: an excellent nanohybrid material for SERS and catalytic applications.

A nanohybrid (NH), having high dispersion of silver nanoparticles (AgNPs) on β-cyclodextrin (β-CD)/graphitic carbon nitride (g-CN), designated as AgNPs/β-CD/g-CN-NH, was synthesized and characterized. It was exploited for a couple of environmental remediation applications like SERS sensing and catalytic reduction of specific organic pollutants in water. It showed excellent SERS activity as a Raman probe for the detection of malachite green (MG).

Silver nanoparticles decorated g-CN: An efficient SERS substrate for monitoring catalytic reduction and selective Hgions detection.

Graphitic carbon nitride supported Ag NPs(AgNPs@g-CN) were synthesized by an in-situ chemical reduction using a green reducing agent, tannic acid. They were characterized by UV-Vis, FTIR, XPS, XRD, FESEM, EDAX and HRTEM. They were very much SERS sensitive, and capable of detecting methylene blue and 4-aminothiophenol at 1 × 10 M and 1 × 10 M, respectively with the corresponding SERS enhancement factor of 1.

Effect of osmolytes on in-vitro aggregation properties of peptides derived from TGFBIp.

Protein aggregation has been one of the leading triggers of various disease conditions, such as Alzheimer's, Parkinson's and other amyloidosis. TGFBI-associated corneal dystrophies are protein aggregation disorders in which the mutant TGFBIp aggregates and accumulates in the cornea, leading to a reduction in visual acuity and blindness in severe cases. Currently, the only therapy available is invasive and there is a known recurrence after surgery.

Multiwalled Carbon Nanotubes/Gold Nanoparticles Hybrid Electrodes for Enzyme-Free Electrochemical Glucose Sensor.

We followed a facile strategy to fabricate glucose sensors using mildly oxidized multiwalled carbon nanotubes (MWCNTs), gold nanoparticles (AuNPs) and thiol acids including mercaptoacetic acid (MAA), mercaptopropionic acid (MPA), and mercaptosuccinic acid (MSA). The thiol acids separately bonded to MWCNTs anchored AuNPs of average diameter 14 nm, and yielded three different nanohybrids; MWCNTs-MAA-AuNPs, MWCNTs-MPA-AuNPs and MWCNTs-MSA-AuNPs. The nanohybrids after coating onto glassy carbon (GC) electrode resulted into enzyme free glucose sensors (GC-MWCNTs-MAA-AuNPs, GC-MWCNTs-MPA-AuNPs and GC-MWCNTs-MSA-AuNPs).

Fabrication of SnS/TiO@GO Composite Coated Glassy Carbon Electrode for Concomitant Determination of Paracetamol, Tryptophan, and Caffeine in Pharmaceutical Formulations.

Designing an electrochemical sensor which is simple, cheap, sensitive, fast, and accurate is inevitable, as it is important in drug quality control, point-of-care diagnosis, and other clinical studies. Sensors for simultaneous determination of paracetamol, tryptophan, and caffeine have not been reported so far, and we report an electrochemical sensor via incorporating tin sulfide (SnS) and titanium dioxide (TiO) on graphene oxide (GO) sheets (SnS/TiO@GO ternary composite) for their separate and simultaneous determination through cyclic voltammetry and differential pulse voltammetry techniques. The surface morphology and structural properties of the composite were characterized by analytical techniques.

Facile synthesis of core-shell nanocomposites Au catalysts towards abatement of environmental pollutant Rhodamine B.

Magnetically recoverable Au nanoparticles immobilized/stabilized on core-shell nanocomposites are synthesized by the combination of suspension polymerization as well as surface initiator atom transfer radical polymerization (SI-ATRP) methods. The magnetic core-shell supported Au nanocatalysts are namely FeO-PAC-AuNPs, FeO-PVBC-g-PAC-AuNPs, FeO-HEA-AuNPs, and FeO-PVBC-g-HEA-AuNPs. Among all the catalysts, FeO-PVBC-g-PAC-Au NPs exhibited an excellent activity in the reduction of Rhodamine B with an apparent rate constant of 10.

Core-Shell Nanostructured FeO-Poly(styrene--vinylbenzyl chloride) Grafted PPI Dendrimers Stabilized with AuNPs/PdNPs for Efficient Nuclease Activity.

Four different novel magnetic core-shell nanocomposites stabilized with Au/Pd nanoparticles (NPs) were prepared by a simple procedure and demonstrated their catalytic activity for effective cleavage of pBR322 DNA. Initially, the FeO-poly(styrene-divinylbenzene-vinylbenzyl chloride) (ST-DVB-VBC) matrix functionalized with 3-aminobenzoic acid was prepared and grafted with PPI-G(2) and PPI-G(3) dendrimers. Each core-shell matrix was immobilized with AuNPs and PdNPs separately.

Real-time assessment of corneal endothelial cell damage following graft preparation and donor insertion for DMEK.

Purpose: To establish a method for assessing graft viability, in-vivo, following corneal transplantation.

Methods: Optimization of calcein AM fluorescence and toxicity assessment was performed in cultured human corneal endothelial cells and ex-vivo corneal tissue. Descemet membrane endothelial keratoplasty grafts were incubated with calcein AM and imaged pre and post preparation, and in-situ after insertion and unfolding in a pig eye model.

Proteomic Analysis of Amyloid Corneal Aggregates from TGFBI-H626R Lattice Corneal Dystrophy Patient Implicates Serine-Protease HTRA1 in Mutation-Specific Pathogenesis of TGFBIp.

TGFBI-associated corneal dystrophies are inherited disorders caused by TGFBI gene variants that promote deposition of mutant protein (TGFBIp) as insoluble aggregates in the cornea. Depending on the type and position of amino acid substitution, the aggregates may be amyloid fibrillar, amorphous globular or both, but the molecular mechanisms that drive these different patterns of aggregation are not fully understood. In the current study, we report the protein composition of amyloid corneal aggregates from lattice corneal dystrophy patients of Asian origin with H626R and R124C mutation and compared it with healthy corneal tissues via LC-MS/MS.

Effect of position-specific single-point mutations and biophysical characterization of amyloidogenic peptide fragments identified from lattice corneal dystrophy patients.

Corneal stromal dystrophies are a group of genetic disorders that may be caused by mutations in the transforming growth factor β-induced () gene which results in the aggregation and deposition of mutant proteins in various layers of the cornea. The type of amino acid substitution dictates the age of onset, anatomical location of the deposits, morphological features of deposits (amyloid, amorphous powder or a mixture of both forms) and the severity of disease presentation. It has been suggested that abnormal turnover and aberrant proteolytic processing of the mutant proteins result in the accumulation of insoluble protein deposits.

Surface Grafted Hyper-Branched Polyglycerol Stabilized Ag and AuNPs Heterogeneous Catalysts for Efficient Reduction of Congo Red.

Six types of insoluble polymer-supported beads immobilized with Ag and AuNPs nanoparticle catalysts were synthesized using newly prepared three different types of polymer-supported poly(styrene)-co-poly(vinyl benzene chloride) matrix (PS-PVBC), surface grafted with (i) triethanolamine (TEA), (ii) glycidyl trimethyl ammonium chloride (GTMAC) and (iii) hyper-branched polyglycerol (HPG) and Ag and AuNPs as a catalytic moiety and thus yield polymer-supported nanoparticle catalysts viz., PS-PVBC-TEA-AgNPs and AuNPs, PS-PVBC-g-GTMAC-AgNPs and AuNPs and PS-PVBC-g-GTMAC-AgNPs and AuNPs catalyst respectively. These bead-shaped heterogonous nanoparticle catalysts were characterized by UV-Vis, FTIR, FESEM, HRTEM and TGA techniques.

pH Induced Conformational Transitions in the Transforming Growth Factor β-Induced Protein (TGFβIp) Associated Corneal Dystrophy Mutants.

Most stromal corneal dystrophies are associated with aggregation and deposition of the mutated transforming growth factor-β induced protein (TGFβIp). The 4(th)_FAS1 domain of TGFβIp harbors ~80% of the mutations that forms amyloidogenic and non-amyloidogenic aggregates. To understand the mechanism of aggregation and the differences between the amyloidogenic and non-amyloidogenic phenotypes, we expressed the 4(th)_FAS1 domains of TGFβIp carrying the mutations R555W (non-amyloidogenic) and H572R (amyloidogenic) along with the wild-type (WT).

Collagen-Based Artificial Corneal Scaffold with Anti-Infective Capability for Prevention of Perioperative Bacterial Infections.

Bacterial infection following implantation of an artificial corneal scaffold is a serious complication. Conventional antibiotic prophylaxis, which includes topical vancomycin application, is limited by low bioavailability, high dosing requirement, and poor patient compliance. The ideal option to overcome these issues is an antibiotic-eluting corneal prosthesis that sustains the local release of drug.

Biochemical properties and aggregation propensity of transforming growth factor-induced protein (TGFBIp) and the amyloid forming mutants.

TGFBI-associated corneal dystrophies are characterized by accumulation of insoluble deposits of the mutant protein transforming growth factor β-induced protein (TGFBIp) in the cornea. Depending on the nature of mutation, the lesions appear as granular (non-amyloid) or lattice lines (amyloid) in the Bowman's layer or in the stroma. This review article emphasizes the structural biology aspects of TGFBIp.

Clinical and genetic aspects of the TGFBI-associated corneal dystrophies.

Corneal dystrophies are a group of inherited disorders localized to various layers of the cornea that affect corneal transparency and visual acuity. The deposition of insoluble protein materials in the form of extracellular deposits or intracellular cysts is pathognomic. Mutations in TGFBI are responsible for superficial and stromal corneal dystrophies.

Drug delivery investigations of quaternised poly(propylene imine) dendrimer using nimesulide as a model drug.

This study describes the demonstration of quaternized poly(propylene imine) dendrimer of generation-3, QPPI (G3) as a drug carrier for poorly soluble drug nimesulide (NMD, an anti-inflammatory drug). QPPI (G3) was prepared by treating the surface amine groups of poly(propylene imine) dendrimer with glycidyltrimethyl ammonium chloride and it was characterized with FTIR, (1)H and (13)C NMR and MALDI-TOF mass spectral techniques. The drug carrying potential of QPPI (G3) was assessed by analyzing drug solubility, in vitro release and cytotoxicity studies.

New surface hydroxylated and internally quaternised poly(propylene imine) dendrimers as efficient biocompatible drug carriers of norfloxacin.

Objectives: This study intended to describe the development of two novel, biocompatible and potential surface hydroxylated quaternary ammonium chloride based poly(propylene imine) (PPI) dendrimers for effective delivery of the drug Norfloxacin (NFN).

Methods: The synthetic pathway involved the hydroxylation and methylation of generation 2 and 3 PPI dendrimers and thus produced surface hydroxylated and internally quaternised PPI dendrimers viz., QPPI-OH (G2) and QPPI-OH (G3), respectively.

Synthesis, characterization, and catalytic activity for hybrids of multi-walled carbon nanotube and amphiphilic poly(propyleneimine) dendrimer immobilized with silver and palladium nanoparticle.

Four types of new multi-walled carbon nanotube (MWCNT) based nanohybrid catalysts were prepared through simple methods. Initially, MWCNT was functionalized with carboxyl group and subsequently bonded with amphiphilic poly(propyleneimine) dendrimer (APPI) having generation (G2) and (G3). They are abbreviated as MWCNT-APPI (G2) and MWCNT-APPI (G3).