Preparation and Characterization of Quaternized Chitosan Coated Alginate Microspheres for Blue Dextran Delivery

BBD Driven Fabrication of Hydroxyapatite Engineered Risedronate Loaded Thiolated Chitosan Nanoparticles and Their In Silico, In Vitro, and Ex Vivo Studies

Risedronate sodium (RIS) exhibits limited bioavailability and undesirable gastrointestinal effects when administered orally, necessitating the development of an alternative formulation. In this study, mPEG-coated nanoparticles loaded with RIS-HA-TCS were created for osteoporosis treatment. Thiolated chitosan (TCS) was synthesized using chitosan and characterized using DSC and FTIR, with thiol immobilization assessed using Ellman's reagent. RIS-HA nanoparticles were fabricated and conjugated with synthesized TCS. Fifteen batches of RIS-HA-TCS nanoparticles were designed using the Box-Behnken design process. The nanoparticles were formulated through the ionic gelation procedure, employing tripolyphosphate (TPP) as a crosslinking agent. In silico activity comparison of RIS and RIS-HA-TCS for farnesyl pyrophosphate synthetase enzyme demonstrated a higher binding affinity for RIS. The RIS-HA-TCS nanoparticles exhibited 85.4 ± 2.21% drug entrapment efficiency, a particle size of 252.1 ± 2.44 nm, and a polydispersity index of 0.2 ± 0.01. Further conjugation with mPEG resulted in a particle size of 264.9 ± 1.91 nm, a PDI of 0.120 ± 0.01, and an encapsulation efficiency of 91.1 ± 1.17%. TEM confirmed the spherical particle size of RIS-HA-TCS and RIS-HA-TCS-mPEG. In vitro release studies demonstrated significantly higher release for RIS-HS-TCS-mPEG (95.13 ± 4.64%) compared to RIS-HA-TCS (91.74 ± 5.13%), RIS suspension (56.12 ± 5.19%), and a marketed formulation (74.69 ± 3.98%). Ex vivo gut permeation studies revealed an apparent permeability of 0.5858 × 10-1 cm/min for RIS-HA-TCS-mPEG, surpassing RIS-HA-TCS (0.4011 × 10-4 cm/min), RIS suspension (0.2005 × 10-4 cm/min), and a marketed preparation (0.3401 × 10-4 cm/min).

Recent advances in cellulose, pectin, carrageenan and alginate-based oral drug delivery systems

Polymers-based drug delivery systems constitute one of the highly explored thrust areas in the field of the medicinal and pharmaceutical industries. In the past years, the properties of polymers have been modified in context to their solubility, release kinetics, targeted action site, absorption, and therapeutic efficacy. Despite the availability of diverse synthetic polymers for the bioavailability enhancement of drugs, the use of natural polymers is still highly recommended due to their easy availability, accessibility, and non-toxicity. The aim of the review is to provide the available literature of the last five years on oral drug delivery systems based on four natural polymers i.e., cellulose, pectin, carrageenan, and alginate in a concise and tabulated manner. In this review, most of the information is in tabulated form to provide easy accessibility to the reader. The data related to active pharmaceutical ingredients and supported components in different formulations of the mentioned polymers have been made available.

Synthesis of Cationic Quaternized Nanolevan Derivative for Small Molecule and Nucleic Acid Delivery

Levan is a biopolymer composed of fructose chains covalently linked by β−2,6 glycosidic linkages. This polymer self−assembles into a nanoparticle of uniform size, making it useful for a wide range of applications. Also, levan exhibits various biological activities such as antioxidants, anti-inflammatory, and anti-tumor, that make this polymer very attractive for biomedical application. In this study, levan synthesized from Erwinia tasmaniensis was chemically modified by glycidyl trimethylammonium chloride (GTMAC) to produce cationized nanolevan (QA-levan). The structure of the obtained GTMAC−modified levan was determined by FT-IR, 1H-NMR and elemental (CHN) analyzer. The size of the nanoparticle was calculated using the dynamic light scattering method (DLS). The formation of DNA/QA-levan polyplex was then investigated by gel electrophoresis. The modified levan was able to increase the solubility of quercetin and curcumin by 11-folds and 205-folds, respectively, compared to free compounds. Cytotoxicity of levan and QA−levan was also investigated in HEK293 cells. This finding suggests that GTMAC−modified levan should have a potential application for drug and nucleic acid delivery.

"Out-of-the-box" Granular Gel Bath Based on Cationic Polyvinyl Alcohol Microgels for Embedded Extrusion Printing

Embedded extrusion printing provides a versatile platform for fabricating complex hydrogel-based biological structures with living cells. However, the time-consuming process and rigorous storage conditions of current support baths hinder their commercial application. This work reports a novel "out-of-the-box" granular support bath based on chemically crosslinked cationic polyvinyl alcohol (PVA) microgels, which is ready to use by simply dispersing the lyophilized bath in water. Notably, with ionic modification, PVA microgels yield reduced particle size, uniform distribution, and appropriate rheological properties, contributing to high-resolution printing. Following by the lyophilization and re-dispersion process, ion-modified PVA baths recover to its original state, with unchanged particle size, rheological properties, and printing resolution, demonstrating its stability and recoverability. Lyophilization facilitates the long-term storage and delivery of granular gel baths, and enables the application of "out-of-the-box" support materials, which will greatly simplify experimental procedures, avoid labor-intensive and time-consuming operations, thus accelerating the broad commercial development of embedded bioprinting.

A synergy between dopamine and electrostatically bound bactericide in a poly (vinyl alcohol) hybrid hydrogel for treating infected wounds

Antibacterial hydrogels have emerged as viable options for battling infections associated with impaired wound healing. It is challenging in developing antibacterial hydrogels that have sustained and stable bactericidal activity while avoiding the use of any agents that may adversely affect safety. In view of this concern, a multi-functional polyvinyl alcohol (PVA)/sodium alginate-dopamine (SA-DA) hydrogel matrix-based wound dressing embedding with bis-quaternary triphenyl-phosphonium salt (BTPP+), that would present long-term intrinsic antimicrobial properties was developed using freeze-thawing (F-T) method herein. DA endows the hydrogel with efficient bacteria capture ability and subsequently the captured bacterial pathogens were in situ killed by electrostatically bound BTPP+, and hence significantly augmented the antibacterial efficacy. Furthermore, DA, co-operating with BTPP+ could promote erythrocyte and platelet aggregation on hydrogels, which ensures hydrogels with improved hemostasis capacity. Thus, this investigation provides a feasible simple avenue for development of long-term intrinsic antimicrobial hydrogel dressings with efficient hemostasis efficacy for infected wounds.

Antibacterial Biodegradable Films Based on Alginate with Silver Nanoparticles and Lemongrass Essential Oil-Innovative Packaging for Cheese

Replacing the petroleum-based materials in the food industry is one of the main objectives of the scientists and decision makers worldwide. Biodegradable packaging will help diminish the environmental impact of human activity. Improving such biodegradable packaging materials by adding antimicrobial activity will not only extend the shelf life of foodstuff, but will also eliminate some health hazards associated with food borne diseases, and by diminishing the food spoilage will decrease the food waste. The objective of this research was to obtain innovative antibacterial films based on a biodegradable polymer, namely alginate. Films were characterized by environmental scanning electron microscopy (ESEM), Fourier-transform infrared spectroscopy (FTIR) and microscopy, complex thermal analysis (TG-DSC-FTIR), UV-Vis and fluorescence spectroscopy. Water vapor permeability and swelling behavior were also determined. As antimicrobial agents, we used silver spherical nanoparticles (Ag NPs) and lemongrass essential oil (LGO), which were found to act in a synergic way. The obtained films exhibited strong antibacterial activity against tested strains, two Gram-positive (Bacillus cereus and Staphylococcus aureus) and two Gram-negative (Escherichia coli and Salmonella Typhi). Best results were obtained against Bacillus cereus. The tests indicate that the antimicrobial films can be used as packaging, preserving the color, surface texture, and softness of cheese for 14 days. At the same time, the color of the films changed (darkened) as a function of temperature and light presence, a feature that can be used to monitor the storage conditions for sensitive food.

Optimization of Thiolated Chitosan Nanoparticles for the Enhancement of in Vivo Hypoglycemic Efficacy of Sitagliptin in Streptozotocin-Induced Diabetic Rats

Sitagliptin (SGN) is an antidiabetic drug used for treatment of diabetes mellitus type II. The objectives of this study were to formulate SGN in form of thiolated chitosan (TC) nanoparticles to enhance the mucoadhesion properties of SGN to the gastrointestinal tract, prolong drug release, decrease side effects, and enhance patient compliance. Seventeen batches of SGN-TC nanoparticles were designed by Box-Behnken design and prepared using the ionic gelation method using tripolyphosphate (TPP) as crosslinking agent. The prepared formulations were evaluated for particle size, entrapment efficiency %, and in vitro drug release. Based on the results of optimization, three formulations (F1-F3) were prepared with different drug polymer ratios (1:1, 1:2, and 1:3). The mucoadhesion study and in vivo hypoglycemic activity of three formulations were evaluated in comparison to free SGN in streptozotocin (STZ)-induced diabetic rats. The seventeen SGN-TC nanoparticles showed small particle sizes, high entrapment efficiency, and prolonged drug release. The concentration of TC polymers had highest effect on these responses. The percentage of SGN-TC nanoparticles adhered to tissue was increased and the release was prolonged as the concentration of TC polymer increased (F3 > F2 > F1). The hypoglycemic effect of SGN-TC nanoparticles was significantly higher than resulted by free SGN. It was concluded that TC nanoparticles had the ability to enhance the mucoadhesion properties of SGN and prolong the drug release. SGN-TC nanoparticles significantly reduced plasma glucose levels compared to free SGN in STZ-induced diabetic rats.

Fabrication of Quaternized Chitosan Nanoparticles Using Tripolyphosphate/Genipin Dual Cross-Linkers as a Protein Delivery System

Various amounts of 2-((acryloyloxy)ethyl)trimethylammonium chloride were grafted onto chitosan (CS) via redox polymerization method to obtain water-soluble quaternized CS (QCS). The QCS nanoparticles loaded with bovine serum albumin (BSA) were then produced by ionic gelation with tripolyphosphate (TPP) and further covalently cross-linked with genipin. The formation of QCS nanoparticles was optimized as a function of monomer grafting yield, QCS/TPP weight ratio, and QCS/genipin weight ratio by Box-Behnken design and response surface methodology. The results showed that QCS nanoparticles prepared with a grafting yield of 50%, QCS/TPP weight ratio of 7.67, and QCS/genipin weight ratio of 60 had a particle size of 193.68 ± 44.92 nm, polydispersity of 0.232, zeta potential of +23.97 mV and BSA encapsulation efficiency of 46.37 ± 2.89%, which were close to the predicted values from mathematical models. In vitro drug release studies at pH 1.2 and pH 7.4 exhibited that the release rate of BSA was significantly decreased and the release period was significantly prolonged after QCS nanoparticles cross-linking with genipin. Therefore, QCS nanoparticles cross-linked with TPP/genipin dual cross-linkers may be a promising protein drug carrier for a prolonged and sustained delivery.

Capecitabine encapsulated chitosan succinate-sodium alginate macromolecular complex beads for colon cancer targeted delivery: in vitro evaluation

The present study aims to investigate the efficacy of the novel biopolymeric complex multiparticulate system consisting of chitosan succinate and alginate for the capecitabine-targeted delivery to colon cancer. A Box-Behnken design was used to optimize the CS-SA beads by considering the effect of three factors: CS (A;X₁), CaCl₂ (B;X₂), and SA (C;X₃), on the response variables Y₁ (EE), Y₂ (Size), and Y₃ (Release). The results of response surface plots allowed an optimized bead to be identified with high drug EE and maximum drug release at colon. The swelling index showed that the beads reached a maximum good swelling at pH 7.4, and nil or little swelling at acidic pH, which proves that the beads completely protect the release of drug. The in vitro release portrayed a maximum release at pH 7.4, due to the large swelling force that was created by electrostatic repulsion between the ionized carboxylic acid groups of the CS-SA network. In vitro cytotoxicity assay (MTT) of CS-SA beads shows inhibition of the proliferation of HT-29 tumour cell to induce apoptosis over a longer period of time. The above results show that CS-SA beads prolong the release of CP in the colonic region, and also enhance antitumor efficacy.