Pooja Doshi

Fabrication of chitosan microspheres using vanillin/TPP dual crosslinkers for protein antigens encapsulation.

Microspheres were prepared from water soluble chitosan using dual vanillin/TPP crosslinkers. Placebo (C1), Bovine serum albumin (BSA) (C2), monovalent tetanus toxoid (TT) (C3) and divalent tetanus (TT) and diphtheria toxoids (DT) (C4) encapsulated microspheres were studied in terms of size (1-4 μm), encapsulation efficiency (75-80%), swelling and mucoadhesion (56-68%). FT-IR, TGA, XRD and SEM characterization of microspheres suggested specific interaction, more thermal stability, amorphous nature and rough surfaces of encapsulated microspheres. EDS confirmed the co-crosslinking and ninhydrin tests were showing higher crosslinking density. Zeta potential was 47.7 to 66.2 +mV indicating the potential stability of the colloidal system. Equilibrium adsorption isotherms described encapsulated microspheres followed the Langmuir isotherm model, suggesting monolayer adsorption of the mucin on microspheres. In-vitro release studies up to four weeks indicated zero order kinetics and obeyed swelling-controlled super case II transport release mechanism. Thus, the present study could be helpful in developing the multivalent oral vaccine.

Physicochemical and thermal characterization of nonedible oilseed residual waste as sustainable solid biofuel.

The present study aims to investigate the potential of nonedible oilseed Jatropha (Jatropha curcas) and Karanja (Pongamia pinnata) defatted residual biomasses (whole seed, kernel, and hull), as solid biofuel. These biomasses showed good carbon contents (39.8-44.5%), whereas, fewer amounts were observed for sulfur (0.15-0.90%), chlorine (0.64-1.76%), nitrogen (0.9-7.2%) and ash contents (4.0-8.7%). Their volatile matter (60.23-81.6%) and calorific values (17.68-19.98 MJ/kg) were found to be comparable to coal. FT-IR and chemical analyses supported the presence of good amount of cellulose, hemicellulose and lower lignin. The pellets prepared without any additional binder, showed better compaction ratio, bulk density and compressive strength. XRF analysis carried out for determination of slagging-fouling indices, suggested their ash deposition tendencies in boilers, which can be overcome significantly with the optimization of the blower operations and control of ash depositions. Thus, overall various chemical, physical properties, thermal decomposition, surface morphological studies and their high biofuel reactivity indicated that residual biomasses of Jatropha and Karanja seeds have high potential to be utilized as a solid biofuel.

Sustainable approach to produce bioethanol from Karanja (Pongamia pinnata) oilseed residue

* Correspondence: pdoshi@chem.unipune.ac.in

Tartrate/tripolyphosphate as co-crosslinker for water soluble chitosan used in protein antigens encapsulation.

In drug delivery research, several toxic chemical crosslinkers and non-toxic ionic crosslinkers have been exploited for the synthesis of microparticles from acetic acid soluble chitosan. This paper hypothesized the implementation of sodium potassium tartrate (SPT) as an alternative crosslinker for sodium tripolyphosphate (TPP) and SPT/TPP co-crosslinkers for synthesis of the microparticles using water soluble chitosan (WSC) for encapsulation of Bovine serum albumin (BSA) as a model protein, and Tetanus toxoid (TT) as a model vaccine. The crosslinking was confirmed by FT-IR, SEM with EDS. The XRD entailed molecular dispersion of proteins and thermal analysis confirmed the higher stability of STP/TPP co-crosslinked formulations. The resultant microparticles were exhibiting crosslinking degree (52-67%), entrapment efficiency (72-80%), particle size (0.3-1.7μm), zeta potential (+24 to 46mV) and mucoadhesion (41-68%). The superiority of SPT over TPP was confirmed by higher crosslinking degree and entrapment efficiency. However, co-crosslinking were advantageous in higher regression values for Langmuir adsorption isotherm, slower swelling tendency and extended 30days controlled in-vitro release study. TT release obeyed the Quasi-Fickian diffusion mechanism for single and cocrosslinked formulations. Overall, in crosslinking of chitosan as biological macromolecules, STP/TPP may be alternative for single ionic crosslinked formulations for protein antigen delivery.

α-Geminal disubstituted pyrrolidine iminosugars and their C-4-fluoro analogues: Synthesis, glycosidase inhibition and molecular docking studies

A simple strategy for the synthesis of α-geminal disubstituted pyrrolidine iminosugars 3a-c and their C-4 fluorinated derivatives 4a-c has been described from d-glucose. The methodology involves the Corey-Link and Jocic-Reeve reaction with 3-oxo-α-d-glucofuranose and nucleophilic displacement reaction to get the furanose fused pyrrolidine ring skeleton with requisite CH2OH/CO2H functionalities at C-3. The fluorine substituent in target molecules was introduced by nucleophilic displacement of -OTf in 9a/9c with CsF. Appropriate manipulation of the anomeric carbon in the furanose fused pyrrolidine ring skeleton afforded α-geminal disubstituted pyrrolidine iminosugars 3a-c and C-4 fluoro derivatives 4a-c. The pyrrolidine iminosugars 3a and 3c were found to be potent inhibitors of α-galactosidase while, the fluoro derivatives 4a and 4b showed strong inhibition of β-glucosidase and β-galactosidase, respectively. These results were substantiated by in silico molecular docking studies.

Preparation and characterization of microencapsulated DwPT trivalent vaccine using water soluble chitosan and its in-vitro and in-vivo immunological properties

The paper explained the microencapsulation of three different antigenic materials viz. Diphtheria toxoid (DT), whole cell pertussis antigens (PT and FHA) and tetanus toxoid (TT) by coacervation method using water soluble chitosan as a polymer crosslinked by vanillin/TPP co-crosslinkers for the development of oral trivalent DwPT vaccine. Instrumental characterization of chitosan microspheres suggested specific interaction with vanillin/TPP, higher thermal stability, amorphous nature, spherical morphology with size less than 2μm along with positive charge density offering mucoadhesive properties. Furthermore, PT and FHA showed higher encapsulation up to 94% followed by TT and DT. Cumulative release rate of DT was (68.47%), TT (73.67%), PT (43%) and FHA (53%). Release kinetics interpreted using DD solver program, indicated protein release followed first order kinetics and obeyed Korsmeyer-peppas model, stating fickian diffusion relates to diffusion, erosion and controlled release rate of the encapsulated toxoids. Application of formulations on caco-2 cell line showed negligible cytotoxic effect and efficient uptake of FITC labelled microspheres. The obtained in-vivo results suggests that the final trivalent DwPT formulation were having successful elicitation of both systemic (IgG) and mucosal (sIgA) immune response in balb/c mice. Overall studies indicated that DwPT formulation could be a suitable alternative to available injectable DaPT vaccine.