Theophylline-loaded pectin-based hydrogels. I. Effect of medium pH and preparation conditions on drug release profile

Metal ions doping effect on the physicochemical, antimicrobial, and wound healing profiles of alginate-based composite

The alginate (Alg) matrix with immobilized hydroxyapatite (HAp) and zinc oxide (ZnO), cross-linked by chitosan (CS) and metal ions (Meⁿ⁺) Ca²⁺, Zn²⁺, and Cu²⁺ was created as a wound dressing. The effect of Meⁿ⁺ and their concentrations on water vapor transition, fluid handling, dehydration, drug release, and healing are shown. Me-containing samples have a lower sorption capacity, than a commercial Kaltostat, however, a much lower degree of their dehydration provides a longer wound wet. The Meⁿ⁺ presence lowers the environmental pH to slightly acidic values promoting healing. Ca²⁺, Zn²⁺, and Cu²⁺ in complexes with CS increase antimicrobial effect against E. coli and S. aureus, slow down the Anaesthesine release, making it compatible with Fickian diffusion in the Zn²⁺ and Cu²⁺ presence, and non-Fickian transport under Ca²⁺ influence. The material promotes the proliferation of the fibroblasts, an increase of collagen fibres, and new arterial and venous capillaries, indicating the intensity of the healing process.

Development and Evaluation of Cellulose Derivative and Pectin Based Swellable pH Responsive Hydrogel Network for Controlled Delivery of Cytarabine

In the present study, pH-sensitive, biodegradable, and biocompatible Na-CMC/pectin poly(methacrylic acid) hydrogels were synthesized using an aqueous free radical polymerization technique and encapsulated by cytarabine (anti-cancer drug). The aim of the project was to sustain the plasma profile of cytarabine through oral administration. Sodium carboxymethyl cellulose (Na-CMC) and pectin were cross-linked chemically with methacrylic acid (MAA) as a monomer, using methylene bisacrylamide (MBA) as cross-linker and ammonium per sulfate (APS) as an initiator. Prepared hydrogel formulations were characterized for their texture, morphology, cytarabine loading efficiency, compositional and structural properties, thermal nature, stability, swelling response, drug release profile (pH 1.2 and pH 7.4), and in-vivo pharmacokinetic evaluation. Cytarabine-loaded hydrogels were also evaluated for their safety profile by carrying out toxicity studies in rabbits. Results demonstrated efficient encapsulation of cytarabine into the prepared network with loading ranging from 48.5-82.3%. The highest swelling ratio of 39.38 and maximum drug release of 83.29-85.27% were observed at pH 7.4, highlighting the pH responsiveness of the grafted system. Furthermore, cytarabine maximum release was noticed over 24 h, ensuring a sustained release response for all formulations. Histopathological studies and hemolytic profiles confirmed that the prepared hydrogel system was safe, biocompatible, and non-irritant, showing no symptoms of any toxicities and degeneration in organs. Moreover, pharmacokinetic estimation of the cytarabine-loaded hydrogel showed a remarkable increase in the plasma half-life from 4.44 h to 9.24 h and AUC from 22.06 μg/mL.h to 56.94 μg/mL.h. This study revealed that the prepared hydrogel carrier system has excellent abilities in delivering the therapeutic moieties in a controlled manner.

Nanocomposite pectin fibers incorporating folic acid-decorated carbon quantum dots

Pectin has recently attracted increasing attention as an alternative biomaterial commonly used in biomedical and pharmaceutical fields. It shows several promising properties, including good biocompatibility, health benefits, nontoxicity, and biodegradation. In this research, novel nanocomposite fibers composed of folic acid-decorated carbon dots (CDs) in pectin/PEO matrix were fabricated using the electrospinning technique, which was never reported previously. Nitrogen-doped and nitrogen, sulfur-doped CDs were synthesized with average diameters of 2.74 nm and 2.17 nm using the one-step hydrothermal method, studied regarding their physicochemical, optical, and biocompatibility properties. The relative Quantum yields of N-CDs and N, S doped CDs were measured to be 54.7 % and 30.2 %, respectively. Nanocomposite fibers containing CDs were prepared, and their morphology, physicochemical properties, conductivity, drug release behavior, and cell viability were characterized. The results indicated that CDs improve fibrous scaffolds' tensile strength from 13.74 to 35.22 MPa while maintaining comparable extensibility. Furthermore, by incorporation of CDs in the prepared fibers conductivity enhanced from 8.69 × 10^-9 S·m^-1 to 1.36 × 10^-4 S·m^-1. The nanocomposite fibrous scaffold was also biocompatible with controlled drug release over 212 h, potentially promising tissue regeneration.

Interaction mechanism between soybean protein isolate and citrus pectin

In this study, citrus pectin (CP) and soybean protein isolate (SPI) were used as raw materials to prepare a complex. The interaction mechanism and structural changes between SPI and CP were deeply studied by fluorescence spectroscopy and Fourier infrared spectroscopy. The results show that CP has a strong quenching effect on SPI's endogenous fluorescence, and with the addition of CP, the endogenous fluorescence intensity of SPI decreased from 13,565.2 to 6067.3. The CP quenching of SPI is static quenching, and the number of combined bits is 1.26. The results of three-dimensional fluorescence spectra showed that the addition of CP reduced the polarity of SPI amino acid residue microenvironment and changed the protein structure. Hydrophobic interaction exists between CP and SPI. The results of three-dimensional fluorescence spectra showed that the addition of CP reduced the polarity of the amino acid residue microenvironment of SPI and changed the protein structure. Fourier transform infrared spectroscopy shows that CP could change the secondary structure of SPI by decreasing the α-helix and β-sheet, increasing β-rotation and irregular curl, destroying the ordered structure of SPI and increasing the polarity of the amino acids exposed to the solution. The microstructure analysis shows that SPI-CP composite system has honeycomb structure and dense pores. From the perspective of reaction thermodynamics, it was found that the addition of CP could improve the thermal stability of SPI and increase the denaturation temperature of SPI from 119.73 to 132.97°C. This study can provide a theoretical basis for the preparation of protein-pectin complexes and provides reference for their application in food grade gels and Pickering emulsions.

Pectin–Zeolite-Based Wound Dressings with Controlled Albumin Release

Hypoalbuminemia can lead to poor and delayed wound healing, while it is also associated with acute myocardial infarction, heart failure, malignancies, and COVID-19. In elective surgery, patients with low albumin have high risks of postoperative wound complications. Here, we propose a novel cost-effective wound dressing material based on low-methoxy pectin and NaA-zeolite particles with controlled albumin release properties. We focused on both albumin adsorption and release phenomena for wounds with excess exudate. Firstly, we investigated albumin dynamics and calculated electrostatic surfaces at experimental pH values in water by using molecular dynamics methods. Then, we studied in detail pectin–zeolite hydrogels with both adsorption and diffusion into membrane methods using different pH values and albumin concentrations. To understand if uploaded albumin molecules preserved their secondary conformation in different formulations, we monitored the effect of pH and albumin concentration on the conformational changes in albumin after it was released from the hydrogels by using CD-UV spectroscopy analyses. Our results indicate that at pH 6.4, BSA-containing films preserved the protein’s folded structure while the protein was being released to the external buffer solutions. In vitro wound healing assay indicated that albumin-loaded hydrogels showed no toxic effects on the fibroblast cells.