Thotapalli Parvathaleswara Sastry

A novel bio-inorganic bone implant containing deglued bone, chitosan and gelatin

With the aim of developing an ideal bone graft, a new bone grafting material was developed using deglued bone, chitosan and gelatin. Deglued bone (DGB) which is a by-product of bone glue industries and has the close crystallographic similarities of hydroxyapatite was used as main component in the preparation of bone implant. Chitosan was prepared from the exoskeleton of prawn (Pinaeus indicus, family Crustaceae) which is a by-product of seafood industries. Chitosan gives toughness to the product and do not allow the DGB particles to wither away when the implant is placed in the defect. Gelatin was used as binder for the preparation of DGB-chitosan composite. The DGB, chitosan and DGB-chitosan-gelatin composite, which were prepared in the laboratory, were analysed for their physicochemical properties by infrared spectroscopy, X-ray diffraction and scanning electron microscopy studies.

Mechanical and microstructure studies on the modification of CA film by blending with PS

DriedMusa paradiciaca (banana) stem and veins of the leaves, which were hitherto discarded as a waste, were collected and used as starting material for the preparation of cellulose and cellulose acetate. This cellulose acetate was mixed with polystyrene to form blend of cellulose acetate-polystyrene in order to provide enhanced stability and extended utility to the end products. The films of these composites or their individual partners were made separately and studied for their mechanical properties, chemical modification and morphological changes. We report here that banana stem is good source of cellulose and that cellulose completely undergoes modification upon esterification.

Preparation, characterization and evaluation of a biopolymeric gold nanocomposite with antimicrobial activity

The present study describes the antimicrobial activity of C‐AuNp‐Amp (chitosan‐capped gold nanoparticles coupled with ampicillin). C‐AuNp‐Amp was synthesized using the wet precipitation method and characterized using FTIR (Fourier‐transform IR) spectroscopy and AFM (atomic force microscopy) techniques. The optimal level of ampicillin concentration that couples with the C‐AuNp nanocomposite was determined by using UV–visible spectroscopy. The agar‐well diffusion method was used to evaluate the antimicrobial activity, and the broth dilution assay was used to determine the MIC (minimum inhibitory concentration). The size of the ellipsoidal C‐AuNp‐Amp particles was found to be in the range of 50–100 nm. The FTIR spectrum confirms the bonding between amino groups of chitosan and carboxylic groups of ampicillin. The maximum coupling of ampicillin with C‐AuNp was found to be 4.07 mg/10 ml. These results revealed the antimicrobial efficacy of C‐AuNp‐Amp and a 2‐fold increase in activity was achieved when compared with that of free ampicillin. By reducing the antibiotic dosage to 50%, the side effects produced by antibiotics can be minimized.

A novel wound dressing material — fibrin–chitosan–sodium alginate composite sheet

The present study describes preparation and characterization of fibrin–chitosan–sodium alginate composite (F–C–SA) in sheet form. F–C–SA composite was prepared and characterized for its physicochemical properties like water absorption capacity, surface morphology, FTIR spectra and mechanical properties. The optimum quantities of fibrin, chitosan and sodium alginate to get better mechanical properties to composite were determined. FTIR spectrum confirmed the interaction between amino groups of chitosan, fibrin and sodium alginate and SEM studies revealed composite nature of the material.

Fish scale collagen sponge incorporated with Macrotyloma uniflorum plant extract as a possible wound/burn dressing material

Application of plant extracts for the burn/wound treatment is followed over the decades as a common practice and it is an important aspect in clinical management. In this study porous collagen sponges (CS) were prepared using fish scales and were incorporated with mupirocin (CSM) and extracts of Macrotyloma uniflorum (CSPE) separately to impart antimicrobial activity to the sponges. The results showed that the addition of plant extract increased the tensile strength of CSPE and stability against collagenase enzyme. FTIR studies have shown the incorporation of plant extract in CSPE, SEM studies have revealed the porous nature of the sponges and XRD patterns have shown the retention of collagen triple helical structure even after the addition of plant extract. CSPE and CSM have exhibited antimicrobial properties. The sponges prepared were analysed for their in vitro biocompatibility studies using fibroblasts and keratinocyte cell lines and the results have shown their biocompatible nature. Based on the results obtained, CS, CSM and CSPE may be tried as a burn/wound dressing materials, initially, in small animals in vivo.

Fish Scale Collagen—A Novel Material for Corneal Tissue Engineering

The ex vivo cultured limbal stem cells over a biocompatible scaffold are used in the management of limbal stem cell deficiency as an ideal replacement for human amniotic membrane (HAM). A novel source of collagen from fish scales (FSC) was used to fabricate the scaffold. In this study, we have evaluated the physicochemical, mechanical, and culture characteristics of FSC and compared with denuded HAM. The cultured corneal cells were characterized by real-time polymerase chain reaction for putative stem cell markers. The swelling ratio, collagenase assay, and microbial resistance of FSC gave better results when compared to those of HAM. The mechanical and physical strengths of FSC were good enough to handle when compared to HAM. Under microscopic observation, epithelial migration was noted at the end of 48 h from limbal explants plated on FSC and on HAM at the end of 72 h. By the end of the 15th day, 90 to 100% confluent growth was seen resembling the morphological features of limbal epithelium. In conclusion, FSCs from a novel renewable biological source were optically clear with sufficient strength, and gave encouraging results in culture studies; the same may be tried as potential candidate for corneal transplantation after in vivo studies.

Synthesis and characterization of biosheet impregnated with Macrotyloma uniflorum extract for burn/wound dressings.

Developing biomaterials having wound healing properties within the search of a common man is the need of hour, particularly in developing and third world countries. Keeping this objective in view we have developed a wound dressing material, in sheet form, containing fish scale collagen (FSC) and physiologically clotted fibrin (PCF), both are by products of aqua food and meat industries respectively. To impart antimicrobial properties to the composite sheet, it was incorporated with Macrotyloma uniflorum plant extract (MPE). SEM pictures have shown that FSC:PCF:MPE composite has fibrous and porous surface which helps in transportation of oxygen as well as absorbing wound fluids and their evaporation. The biomaterials have shown 100% biocompatibility and the percentage cell viability was found to be above 89%. The FSC:PCF:MPE biocomposite film with required mechanical strength, biocompatibility and antimicrobial properties can be tried as a burn/wound dressing material.

Effect of growth factors and pro-inflammatory cytokines by the collagen biocomposite dressing material containing Macrotyloma uniflorum plant extract—In vivo wound healing

Open burn wounds require proper dressings for faster healing and to prevent infection. In the present study, a wound dressing material in sheet form, containing fish scale collagen (FSC), physiologically clotted fibrin (PCF) and Macrotyloma uniflorum plant extract (MPE) was applied on the experimental wounds of rats. It was found that MPE accelerated wound healing, by suppressing the cyclooxygenase-2 (COX-2) and inducible nitric oxide synthases (iNOS) expressions thereby reduced inflammation. It has influenced the regulation of growth factors such as vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), epidermal growth factor (EGF) and transforming growth factor (TGF-β). The biocomposite sheet has enhanced collagen synthesis and down regulated the matrix metalloproteinases (MMPs), thereby helped faster healing of wounds. The results suggest that the incorporation of MPE played an important role in enhancing the wound healing rate. The FSC-PCF biosheet containing MPE may be further tried on the clinical wounds of small and large animals before application on to humans.

Bio-modified carbon nanoparticles loaded with methotrexate Possible carrier for anticancer drug delivery

The modification of carbon nanoparticles (CNPs) using biological molecules is important in the field of chemical biology, as the CNPs have the potential to deliver the drugs directly to the targeted cells and tissues. We have modified the CNPs by coating bovine serum albumin (BSA) on their surfaces and loaded with methotrexate (Mtx). Infrared spectra have revealed the coating of BSA and Mtx on CNP (CBM). Scanning electron microscopy (SEM) and atomic force microscope (AFM) pictures have exhibited the spherical nature of the composite and coating of the proteins on CNPs. The prepared CBM biocomposite has exhibited a sustained release of drug. MTT assay using A549 lung cancer cell lines has revealed 83% cell death at 150 μg/ml concentration of CBM. These results indicate that CNPs based biocomposites may be tried as therapeutic agents in treatment of cancer like diseases.

Fibrin–Chitosan–Gelatin Composite Film: Preparation and Characterization

Composites, in film form, containing physiologically clotted fibrin, chitosan and gelatin were prepared and crosslinked with glutaraldehyde. The films were characterised for their IR spectroscopy, water absorption capacity (WAC) at different pH conditions, mechanical properties and scanning electron microscopy (SEM). Fibrin+gelatin films gave higher WAC values in all the pH ranges (2,7 and 10) studied. However, with the addition of chitosan, the WAC values of the composite decreased. This was attributed to the crosslinking of glutaraldehyde with the hydrophilic groups available on chitosan and gelatin/fibrin. The amount of individual constituents, which gave maximum tensile strength to the FCG composite, was optimized. SEM pictures of the FCG have exhibited the fibrous and porous nature of the composite.