An Insight on the Swelling, Viscoelastic, Electrical, and Drug Release Properties of Gelatin–Carboxymethyl Chitosan Hydrogels

<p>The present study reports the in-depth analysis of the gelatin–carboxymethyl chitosan hydrogels. The composite system formed phase-separated hydrogels, which is confirmed by scanning electron microscopy. The swelling of the carboxymethyl chitosan-containing hydrogels was lower than the gelatin hydrogel. Macroscale deformation study using a static mechanical tester indicated a viscoelastic nature of the hydrogels. A decrease in the impedance of the hydrogels was observed with an increase in the carboxymethyl chitosan content. The drug release from the hydrogels was predominantly Fickian diffusion mediated and was released in its active form. The results suggested the potential use of the hydrogels as drug delivery matrices.</p

Evaluation of poly(L-lactide) and chitosan composite scaffolds for cartilage tissue regeneration

<p>The present study delineates the development of chitosan and poly(L-lactide) (PLLA) scaffolds cross-linked using a mixture of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC), n-hydroxysuccinimide (NHS), and chondroitin sulfate (CS) for cartilage tissue engineering applications. Chitosan and PLLA were varied in concentration for developing scaffolds and prepared by freeze-drying method. The various scaffolds were studied using scanning electron microscopy (SEM), porosity by mercury intrusion porosimeter, and the molecular interactions among polymers using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) studies. Differential scanning calorimetry was used to predict the thermal properties of the scaffolds. The mechanical properties of the scaffolds were studied using static mechanical tester. The ability of the scaffolds to support chondrocyte proliferation was also studied. The microscopy suggests that the pore size of the scaffolds varied with the composition in the range of 38–172 μm and the porosities in the range of 73–93%. The XRD and the FTIR studies suggested that an alternation in the composition of the scaffolds altered the molecular interactions among the scaffold components. An increase in the chitosan content enhanced the swelling property. The degradation of the scaffolds was least when the proportion of chitosan and PLLA was in the ratio of 70:30. The <i>in vitro</i> cell proliferation study suggested that the developed scaffolds were able to support chondrogenesis, the glycosaminoglycan (GAG) content of the mature chondrocyte was 40 μg/ml and the viability was approximately 90%. Hence, the so designed scaffolds may be tried for cartilage tissue engineering applications.</p

Mango Butter Emulsion Gels as Cocoa Butter Equivalents: Physical, Thermal, and Mechanical Analyses

The search for cocoa butter equivalents in food and pharmaceutical industries has been gaining importance. In the present study, mango butter was explored as cocoa butter equivalent. Aqueous gelatin solution (20% w/w) containing cocoa butter and mango butter water-in-oil (fat) type emulsion gels were prepared by hot emulsification method. XRD and DSC melting profiles suggested the presence of unstable polymorphic forms (α and β′) of fats in the emulsion gels. The crystal size and solid fat content analyses suggested that the presence of aqueous phase might have hindered the transformation of unstable polymorphic forms to stable polymorphic form (β) in the emulsion gels. Fat crystals in the emulsion gels were formed by instantaneous nucleation via either uni- or bidimensional growth (Avrami analysis). The viscoelastic nature of the emulsion gels was evaluated by modified Peleg’s analysis (stress relaxation study). Results inferred that the physical, thermal, and mechanical properties of mango butter emulsion gels are comparable to those of cocoa butter emulsion gels. On the basis of preliminary studies, it was suggested that the mango butter emulsion gels may have potential to be used as cocoa butter equivalents

Synthesis of Vegetable Fat Containing Chitosan Microparticles with Improved Physical and Delivery Properties

<p>The present study describes the encapsulation of vegetable fats (cocoa butter and mango butter) within chitosan microparticles by double emulsion technique to prevent leaching of the internal apolar phase. Leaching studies suggested negligible leaching of the internal phase (∼12–14%) when the fats were encapsulated as compared to the control (∼40%). Fourier transform infrared spectroscopy and differential scanning calorimeter studies confirmed the successful encapsulation of fats. The release of drug (ciprofloxacin) from the microparticles was diffusion and erosion mediated and were capable to elicit antimicrobial activity against <i>Escherichia coli</i>. The study suggests that the developed microparticles have the potential for controlled delivery of antimicrobials.</p

Development and Characterization of Soy Lecithin and Palm Oil-based Organogels

<div><p>Preparation and characterization of soy lecithin (SL) and palm oil (PO) based organogels have been reported in this study. The optimization of the composition of the organogels was carried out by varying the proportions of SL, PO and water. Microscopic studies suggested the presence of aqueous phase either as spherical droplets or fluid filled fibers or both, depending on the composition of the organogels. FTIR study indicated strong intermolecular hydrogen bonding among the organogel components. The release of metronidazole (model drug, MZ) suggested diffusion mediated drug release. MZ loaded organogels showed good antimicrobial property against <i>B. subtilis</i> and <i>E. coli.</i></p> </div

Novel agar–stearyl alcohol oleogel-based bigels as structured delivery vehicles

<p>The present study describes the synthesis of novel bigels as delivery matrices for controlled delivery applications. The bigels were prepared by mixing agar hydrogel and stearyl alcohol oleogel in different proportions. The microscopic analysis of the bigels suggested the formation of biphasic bigels at lower proportions of oleogel and bicontinuous bigel at higher proportions. Stress relaxation study was used to analyze the mechanical properties. The viscoelastic property of the bigels was estimated by modeling the relaxation profile using Weichert model of viscoelasticity. The analysis of the electrical property of the bigels showed an increase in the impedance values as the oleogel content was increased. Further, a corresponding decrease in the electrical stability of the bigels was observed with an increase in the oleogel proportion. The analysis was prepared using (RQ)Q equivalent electrical circuit model. The ciprofloxacin hydrochloride release from the bigels was predominantly diffusion-mediated as analyzed by Korsmeyer–Pappas and Peppas–Sahlin models.</p

Preparation, Characterization and Assessment of the Novel Gelatin–tamarind Gum/Carboxymethyl Tamarind Gum-Based Phase-Separated Films for Skin Tissue Engineering Applications

<p>The current study delineates the development of novel gelatin–tamarind gum/carboxymethyl tamarind gum-based phase-separated films for probable skin tissue engineering applications. Polyethylene glycol was used as plasticizer. The films were characterized thoroughly using mechanical tester and impedance analyzer. Cell proliferation ability and drug release properties of the films were investigated. Mechanical studies indicated composition-dependent stress relaxation properties. Polysaccharide containing films supported better proliferation of human keratinocytes as compared to control. Drug-loaded films showed good antimicrobial properties against <i>Escherichia coli</i>. Analysis of the results indicated that the prepared films may be tried as matrices for skin tissue engineering.</p

Development and characterization of gelatin-tamarind gum/carboxymethyl tamarind gum based phase-separated hydrogels: a comparative study

<div><p>The purpose of this research was to synthesize and characterize gelatin and tamarind gum (TG)/carboxymethyl tamarind (CMT) gum-based phase-separated hydrogels. The hydrogels were thoroughly characterized using bright-field microscope, FTIR spectroscope, differential scanning calorimeter, mechanical tester, and impedance analyzer. The mucoadhesivity, biocompatibility, and swelling property of the hydrogels were also evaluated. The antimicrobial efficiency of ciprofloxacin (model antimicrobial drug) loaded hydrogels was studied against <i>E. coli</i>. The <i>in vitro</i> drug release was carried out in both gastric and intestinal pHs. Microstructural analysis suggested the formation of phase-separated hydrogels. FTIR studies suggested that CMT gum altered the secondary structure of the gelatin molecules. Presence of the polysaccharides within the hydrogels resulted in the increase in the enthalpy and entropy for evaporation of the moisture from the hydrogels. The mechanical studies indicated viscoelastic nature of the hydrogels. Electrical analysis suggested an increase in the impedance of the hydrogels in the presence of the TG. The presence of CMT gum resulted in the decrease in the impedance of the hydrogels. The hydrogels exhibited good mucoadhesivity, biocompatibility, and pH-dependent swelling behavior. The drug-loaded hydrogels showed good antimicrobial activity and the drug release from the hydrogels was pH dependent and diffusion mediated.</p></div

Understanding the Effect of Tamarind Gum Proportion on the Properties of Tamarind Gum-Based Hydroethanolic Physical Hydrogels

<p>The present study reports the analysis of properties of tamarind gum-based hydroethanolic physical hydrogels. The extent of hydrogen bonding in hydrogels decreased with an increase in tamarind gum content. The hydrogel with the highest tamarind gum content was found to be highly stable in terms of mechanical properties. There was a decrease in the resistive component of the hydrogels with an increase in tamarind gum content. The drug release from the hydrogels increased with an increase in the tamarind gum content. The antimicrobial activity of the drug-loaded hydrogels against <i>Escherichia coli</i> was excellent.</p

Potential Use of Nucleic Acids as a Preceramic Polymer to Synthesize Nanodiamond-Embedded Phosphate Glass for Hard Tissue Engineering

In recent years, nucleic acid has emerged as a versatile molecule that has been strategically used in material synthesis and biomedical applications. Keeping in mind the presence of the phosphate group, a glass former in the nucleic acids, we synthesized a transparent glass-like material by the thermal treatment of nucleic acids (DNA and RNA) at 900 °C at atmospheric pressure. Characterization of this material by transmission electron microscopy, X-ray photoelectron spectroscopy, and confocal fluorescence microscopy suggested the presence of in situ-formed nanodiamonds within the phosphate glass matrix. The molecular structure of glass investigated by X-ray photoelectron and infrared spectroscopy indicated a nearly equal proportion of metaphosphates and smaller phosphate units (pyro- and ortho-phosphate) that form the phosphate glass matrix. Thereafter, in vitro biological experiments showed that the nucleic acid-derived glass was non-toxic and cytocompatible, enhanced extracellular matrix secretion, and increased intracellular alkaline phosphatase activity, with potential application in hard tissue engineering. Our work offers insights into nanodiamond synthesis at atmospheric pressure and proves that nucleic acids could be used as a precursor to making an innovative glass-ceramic biomaterial