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

Modeling and characterization of lenalidomide-loaded tripolyphosphate-crosslinked chitosan nanoparticles for anticancer drug delivery

Tripolyphosphate-crosslinked chitosan (TPPCS) nanoparticles were employed in the encapsulation of lenalidomide (LND) using a straightforward ionic cross-linking approach. The primary objectives of this technique were to enhance the bioavailability of LND and mitigate inadequate or overloading of hydrophobic and sparingly soluble drug towards cancer cells. In this context, a quantum chemical model was employed to elucidate the characteristics of TPPCS nanoparticles, aiming to assess the efficiency of these nanocarriers for the anticancer drug LND. Fifteen configurations of TPPCS and LND (TPPCS /LND1-15) were optimized using B3LYP density functional level of theory and PCM model (H2O). AIM analysis revealed that the high drug loading capacity of TPPCS can be attributed to hydrogen bonds, as supported by the average binding energy (168 kJ mol-1). The encouraging theoretical results prompted us to fabricate this drug delivery system and characterize it using advanced analytical techniques. The encapsulation efficiency of LND within the TPPCS was remarkably high, reaching approximately 87 %. Cytotoxicity studies showed that TPPCS/LND nanoparticles are more effective than the LND drug. To sum up, TPPCS/LND nanoparticles improved bioavailability of poorly soluble LND through cancerous cell membrane. In light of this accomplishment, the novel drug delivery route enhances efficiency, allowing for lower therapy doses.

Design of Experiment Approach to Modeling the Effects of Formulation and Drug Loading on the Structure and Properties of Therapeutic Nanogels

The physical properties of nanoparticles may affect the uptake mechanism, biodistribution, stability, and other physicochemical properties of drug delivery systems. This study aimed to first develop a model exploring the factors controlling the nanogel physical properties using a single drug (propranolol), followed by an evaluation of whether these models can be applied more generally to a range of drugs. Size, polydispersity, ζ potential, and encapsulation efficiency were investigated using a design of experiment (DOE) approach to optimize formulations by systematically identifying the effects of, and interactions between, parameters associated with nanogel formulation and drug loading. Three formulation factors were selected, namely, chitosan concentration, the ratio between the chitosan and cross-linker─sodium triphosphate─and the ratio between the chitosan and drug. The results indicate that the DOE approach can be used not only to model but also to predict the size and polydispersity index (PDI). To explore the application of these prediction models with other drugs and to identify the relationship between the drug structure and nanogel properties, nanogels loaded with 12 structurally distinct drugs and 6 structurally similar drugs were fabricated at the optimal condition for propranolol in the model. The measured size, PDI, and ζ potential of the nanogels could not be modeled using distinct DOE parameters for dissimilar drugs, indicating that each drug requires a separate analysis. Nevertheless, for drugs with structural similarities, various linear and nonlinear trends were observed in the size, PDI, and ζ potential of nanogels against selected molecular descriptors, indicating that there are indeed relationships between the drug molecular structure and the performance outcomes, which may be modeled and predicted using the DOE approach. In conclusion, the study demonstrates that DOE models can be applied to model and predict the influence of formulation and drug loading on key performance parameters. While distinct models are required for structurally unrelated drugs, it was possible to establish correlations for the drug series investigated, which were based on polarity, hydrophobicity, and polarizability, thereby elucidating the importance of the interactions between the drug and the nanogels based on the nanogel properties and thus deepening the understanding of the drug-loading mechanisms in nanogels.

Improved accumulation of TGF-β by photopolymerized chitosan/silk protein bio-hydrogel matrix to improve differentiations of mesenchymal stem cells in articular cartilage tissue regeneration

Articular cartilage regeneration is a challenging process due to its inadequate ability of self-recovering biological mechanisms. The progresses of cartilage tissue engineering is supported to overwhelmed the repairing difficulties and degenerative diseases. The main goal of the present study is to design biomaterials with suitable physico-chemical, mechanical and biological properties for the carrier of growth factor and improving differentiation of mesenchymal stem cell into damaged cartilage tissues. Herein, TGF-β loaded hydrogel network was prepared through the chemical interactions between vinyl group of natural polymers. Fourier-transform infrared spectroscopy results show the characteristic peaks at 3074 cm^-1, 1713 cm^-1, and 810 cm^-1, which confirm the existence of the vinyl group and successful formation of maleoyl functionalized Chitosan (MCh). The obtained MCh was freely dissolved in the distilled water up to 8% (w/v). X-ray photoelectron spectroscopy survey spectral results show a peak at 289.0 eV which revealed that the OCO and DS were 1.2% and also evidenced the methacryl substitution of Silk fibroin (SF) nanoformulations. The weight loss and mechanical test were analyzed and the results showed that MSF acts as a foremost crosslinking point with MCh through the reaction between the methacrylate groups of MSF and maleoyl groups of MCh which led to enhancing the density and improved the compressive strength. The maximum drug release activity was recorded in the TGF-β loaded MCh@MSF hydrogel compared to bare MCh hydrogel. Further, the TGF-β loaded MCh@ MSF hydrogel exhibited the cell viability percentage nearly at 79-102% for MC3T3-E1 and 88-104% for BMDSCs. Similarly, the TGF-β loaded MCh@MSF exhibited the highest inhibitory activity against E. coli (83%) than S. aureus (67%). Overall, this study concluded the TGF-β loaded MCh@MSF showed better biocompatibility and could be utilized in the field of cartilage tissue engineering.

Zinc and manganese substituted hydroxyapatite/CMC/PVP electrospun composite for bone repair applications

Zn-Mn HAP (Zinc and Manganese substituted Hydroxyapatite), CMC (Carboxymethyl cellulose)/PVP (Polyvinyl pyrrolidone) and (Zn-Mn HAP)/CMC/PVP (Zn = Mn = 0.05, 0.1 M) were prepared by hydrothermal and electrospinning methods respectively. The prepared composites were characterized using powder X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDAX) to examine the phase formation, functional groups and surface morphology. FTIR spectra of the composite confirmed the funcitonal groups present in the composite. SEM images showed the fiber formation and the incorporation of Zn-Mn HAP into the fiber structures. The physical properties like porosity, swelling and tensile strength was studied for the prepared composites. 0.1 M of (Zn-Mn HAP)/CMC/PVP (20, 40, 60 wt% of Zn-Mn HAP composite) showed good physical properties, in which the 60 wt% showed 98% of porosity with least swelling and the tensile strength was measured to be 67 MPa. Highest zone of inhibition was observed against the microbial organisms using this 60 wt% of 0.1 M of (Zn-Mn HAP)/CMC/PVP composite and it was also found to be hemocompatible with hemolysis value less than 3% when compared to other composites. The biocompatibility of the composite was evaluated using human osteoblast cells (HOS).

Phosphorylated Zein as Biodegradable and Aqueous Nanocarriers for Pesticides with Sustained-Release and anti-UV Properties

Zein's prevalent hydrophobic character is one of the major challenges associated with ineffective utilization as an aqueous nanocarrier for pesticides. Herein, we report an effective approach to hydrophilic modification of zein by phosphorylation using nontoxic sodium tripolyphosphate (STP), thereby improving the water-solubility, foliage wettability, and adhesion ability of zein as a nanocarrier for sustained release of pesticides. The procedure relied on zein grafted with STP via N- and O- phosphate bonds and encapsulation of avermectin (AVM) as a hydrophobic model drug using phosphorylated zein (P-Zein), which achieved pH sensitivity to controlled release of AVM in various applicable environments. The chemical interaction between zein and STP was confirmed by Fourier transform infrared, thermogravimetric analysis, and differential scanning calorimetric. Scanning electron microscopy, dynamic light scattering, and zeta potential technique were applied to investigate their structural characteristics and stability, from which it was found that AVM encapsulated in P-Zein (AVM@P-Zein) formed uniform nanoparticles with average sizes in the range of 174-278 nm under different conditions, and had an excellent stability in aqueous solution. Besides, AVM@P-Zein facilitated the wettability on the foliage surface evidenced from contact angle values owing to the amphiphilic character after phosphorylation as well as enhanced the adhesion ability between liquid and leaf, restricting the pesticide runoff. Ultraviolet-visible spectroscopy was employed to explore the anti-UV property and encapsulation as well as release behavior, which revealed that the presence of P-Zein like a shell protects AVM from UV photolysis with encapsulation efficiency of approximately 81.52%, and the release of AVM from P-Zein showed pH-responsive behavior ascribed to protonation and deprotonation of phosphate under various pH conditions fitting to Elovich kinetic model, achieving the relatively more rapid release under acidic conditions. More importantly, AVM@P-Zein retained the toxicity for insecticidal effect.

The Synergism of Platinum-Gold Bimetallic Nanoconjugates Enhances 5-Fluorouracil Delivery In Vitro

Nanoparticle application has significantly impacted the field of medicine. The need to develop novel drugs with higher therapeutic potential has stimulated the development of innovative delivery strategies to mitigate the potent side effects associated with known chemotherapeutic drugs. This paper describes the synthesis of platinum-gold bimetallic nanoparticles (PtAuBNps), their functionalisation with chitosan, and entrapment of the anticancer drug 5-fluorouracil (5-FU). All PtAuBNps and their drug nanocomposites were physico-chemically characterised, displaying desirable properties with regards to shape, size (<120 nm) and colloidal stability. 5-FU binding and loading capacities in PtAuBNps were found to be 90.17% and 22.56%, respectively. In vitro cytotoxicity profiles determined using the MTT and SRB assays reflected up to 65% cell death in the MCF-7, HepG2 and Caco-2 cell lines. These nanocomposites exhibited excellent physiochemical attributes, high specificity towards cancer cells, with a pH-sensitive drug release in a simulated acidic tumour microenvironment through zero-order release kinetics. In addition, they possessed the potential to traverse the mucosal lining facilitating oral drug administration. Overall, 5-FU encapsulation improved the bioavailability of the drug in cancer cells, with the promise of enhancing its therapeutic effect, biocompatibility and safety. These positive results highlight PtAuBNps as promising in vitro delivery systems and merits future in vivo research.

Prebiotic-Like Effects of Water Soluble Chitosan on the Intestinal Microflora in Mice

In the present work, water soluble chitosan (WSC) was prepared and growth curves of Lactobacillus delbrueckii and Escherichia coli were examined in vitro. In vivo, mice were randomly divided into three groups (10 mice in each group), treated with water, 1 g/kg WSC and 0.25 g/kg of WSC respectively for 24 days. Subsequently, levofloxacin (65 mg/kg) was given for 6 days. The dynamic changes of bacterial communities were evaluated by denaturing gradient gel electrophoresis periodically. L. delbrueckii and E. coli have been inhibited by WSC in vitro. The bacteria from the genera of Bacteroides, Lactobacillus, Enterococcus and Devosia were dominant gut flora in the intestinal tract of mice. The growth of Lactobacillus has been dramatically stimulated, whereas Enterococcus faecium and Parabacteroides distasonis which were opportunistic bacterial pathogens have been inhibited. So WSC can be considered as a new food supplement to protect the intestinal microflora and regulate imbalance.

Enhancement of temozolomide stability by loading in chitosan-carboxylated polylactide-based nanoparticles

In the presented work, amphiphilic nanoparticles based on chitosan and carboxy-enriched polylactic acid have been prepared to improve the stability of the pro-drug temozolomide in physiological media by encapsulation. The carrier, with a diameter in the range of 150-180 nm, was able to accommodate up to 800 μg of temozolomide per mg of polymer. The obtained formulation showed good stability in physiological condition and preparation media up to 1 month. Temozolomide loaded inside the carrier exhibited greater stability than the free drug, in particular in simulated physiological solution at pH 7.4 where the hydrolysis in the inactive metabolite was clearly delayed. CS-SPLA nanoparticles demonstrated a pH-dependent TMZ release kinetics with the opportunity to increase or decrease the rate. Mass spectroscopy, UV-Vis analysis, and in vitro cell tests confirmed the improvement in temozolomide stability and effectiveness when loaded into the polymeric carrier, in comparison with the free drug.