A pH-sensitive chitosan-tripolyphosphate hydrogel beads for controlled glipizide delivery

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.

Hydrogel-based Drug Delivery System in Diabetes Management

BACKGROUND

It is estimated that there are over 200 million people living with diabetes mellitus (DM) all over the world. It is a metabolic condition caused by decreased insulin action or secretion. Diabetes Mellitus is also known as Type 2 Diabetes Mellitus. Type 1 diabetes mellitus and type 2 diabetes mellitus are the two most common types of DM. Treatment for type 1 diabetes often consists of insulin replacement therapy, while treatment for type 2 diabetes typically consists of oral hypoglycemics.

OBJECTIVES

Conventional dosing schedules for the vast majority of these medications come with a number of drawbacks, the most common of which are frequent dosing, a short half-life, and low bioavailability. Thus, innovative and regulated oral hypoglycemic medication delivery methods have been developed to reduce the limitations of standard dose forms.

METHODS

The studies and reviews published under the title were looked up in several databases (including PubMed, Elsevier, and Google Scholar).

RESULTS

Hydrogels made from biopolymers are three-dimensional polymeric networks that can be physically or chemically crosslinked. These networks are based on natural polymers and have an inherent hydrophilic quality because of the functional groups they contain. They have a very high affinity for biological fluids in addition to a high water content, softness, flexibility, permeability, and biocompatibility. The fact that these features are similar to those of a wide variety of soft living tissues paves the way for several potentials in the field of biomedicine. In this sense, hydrogels offer excellent platforms for the transport of medications and the controlled release of those drugs. Additionally, biopolymer-based hydrogels can be put as coatings on medical implants in order to improve the biocompatibility of the implants and to prevent medical diseases.

CONCLUSION

The current review focuses on the most recent advancements made in the field of using biopolymeric hydrogels that are physically and chemically crosslinked, in addition to hydrogel coatings, for the purpose of providing sustained drug release of oral hypoglycemics and avoiding problems that are associated with the traditional dosage forms of oral hypoglycemics.

Enzymatic time-temperature indicator with cysteine-loaded chitosan microspheres/silver nanoparticles

A time-temperature indicator (TTI) based on acid-base reaction was developed by applying a new pH dye composed of cysteine-loaded chitosan (Cys-CS) microspheres and silver nanoparticles (AgNPs). It was hypothesized that cysteine released by the disintegration of Cys-CS microspheres at a critical pH would cause AgNPs to aggregate, leading to color change. Cys-CS microspheres were produced as water-in-oil (paraffin oil, MCT oil, soybean oil) emulsions according to the KOH addition method. An enzymatic TTI was made using glucose oxidase, glucose, and catalase. Only paraffin oil produced Cys-CS microspheres (average diameter, 335 ± 100 µm), whereas the others did not, probably due to saponification with KOH. FTIR analysis confirmed that cysteine was encapsulated in the microspheres. The microspheres disintegrated at pH 6.18 in a titration test. The TTI pH gradually decreased and showed a sudden color change at pH 6.10, which was similar to the critical pH of microsphere disintegration.

Current Trends in Biomedical Hydrogels: From Traditional Crosslinking to Plasma-Assisted Synthesis

The use of materials to restore or replace the functions of damaged body parts has been proven historically. Any material can be considered as a biomaterial as long as it performs its biological function and does not cause adverse effects to the host. With the increasing demands for biofunctionality, biomaterials nowadays may not only encompass inertness but also specialized utility towards the target biological application. A hydrogel is a biomaterial with a 3D network made of hydrophilic polymers. It is regarded as one of the earliest biomaterials developed for human use. The preparation of hydrogel is often attributed to the polymerization of monomers or crosslinking of hydrophilic polymers to achieve the desired ability to hold large amounts of aqueous solvents and biological fluids. The generation of hydrogels, however, is shifting towards developing hydrogels through the aid of enabling technologies. This review provides the evolution of hydrogels and the different approaches considered for hydrogel preparation. Further, this review presents the plasma process as an enabling technology for tailoring hydrogel properties. The mechanism of plasma-assisted treatment during hydrogel synthesis and the current use of the plasma-treated hydrogels are also discussed.

Bioactivity of star-shaped polycaprolactone/chitosan composite hydrogels for biomaterials

Recently, our group reported the synthesis and fabrication of composite hydrogels of chitosan (CS) and star-shaped polycaprolactone (stPCL). The co-crosslink of modified stPCL with carboxyl at the end chain (stPCL-COOH) provided good mechanical properties and stability to the composite hydrogels. This research presents the bioactivities of composite hydrogels showing a potential candidate to develop biomaterials such as wound dressing and bone tissue engineering. The bioactivities were the antibacterial activity, cell viability, skin irritation, decomposability, and ability to attach ions for apatite nucleation. The results showed that all the composite hydrogels were completely decomposed within 2 days. The composite hydrogels had better antibacterial activity and higher efficiency to Gram-negative (Escherichia coli) than to Gram-positive (Staphylococcus epidermidis) bacteria. The composite hydrogels were studied for cell viability based on MTT assay and skin irritation on rabbit skin. The results indicated high cell survival more than 80% and no skin irritation. In addition, the results showed that calcium and phosphorous were preferentially attached to the composite hydrogel surface to grow apatite crystal (Ca/P ratio 1.86) compared to attaching to the chitosan hydrogel (Ca/P ratio 1.48) in 21 days of testing.

Transdermal Glipizide Delivery System Based on Chitosan-Coated Deformable Liposomes: Development, Ex Vivo, and In Vivo Studies

The current study aimed to develop and evaluate a sustained-release transdermal Glipizide (GLP) film to overcome its oral administration problems. Chitosan (CS)-coated deformable liposomes (DLs) were utilized to enhance the drug transdermal delivery. The formulations were characterized in terms of particle size, zeta potential, entrapment efficiency (EE%), vesicle deformability, morphology, stability, and in vitro release. Transdermal films of chosen formulations were prepared by the solvent casting technique, and an ex vivo study throughout rat skin was also performed. Moreover, a pharmacokinetics (PK) study was carried out and blood glucose levels were estimated. All the liposomes were in the nanometer range and a high EE% was obtained from DLs compared to conventional liposomes (CL). The prepared formulations showed a high stability and the DLs exhibited a high deformability compared to CL. The in vitro release study confirmed the sustained release of GLP from both CL and DL and a more pronounced sustained release of GLP was detected after coating with CS. Moreover, GLP was shown to efficiently permeate through the rat skin from transdermal films by an ex vivo permeation test. The transdermal films showed a promising PK profile in the rat as compared with oral GLP. Most importantly, GLP-CS-DL1 demonstrated a higher hypoglycemic effect, confirming the possibility of systemic action by the local topical delivery of GLP.

Preparation and Nanoencapsulation of Lectin from Lepidium sativum on Chitosan-Tripolyphosphate Nanoparticle and Their Cytotoxicity against Hepatocellular Carcinoma Cells (HepG2)

Lectins are the oligomeric sugar-specific glycoprotein of nonimmune origin, are involved in the multiple biological recognition process, and have the capacity to perform a wide variety of physiological functions including antifungal, antiviral, antitumor, and cell agglutination. The main objective of the current study was to prepare lectin protein-loaded chitosan-TPP nanoparticles via ionic gelation methods with different CS/TPP ratios and to investigate anticancer potential against HepG2 cells. The best ratio showed the mean particle size (298.10 ± 1.9 nm, 21.05 ± 0.95 mv) with optimal encapsulation efficiencies of 52.435 ± 0.09%. The cytotoxicity was evaluated against HepG2 cells, and IC₅₀ values obtained were 265 μg/ml for lectin protein and 105 μg/ml for lectin-loaded chitosan-TPP nanoparticles, respectively. The mRNA expression of proliferation markers like GPC3 was significantly decreased in hepatocellular carcinoma cells (HepG2) during lectin protein-loaded chitosan-TPP nanoparticle treatment. Apoptotic genes that indicating a marked increase in expression are Caspase 3, p53, and Bax, while Bcl2 and AFP showed a downregulation of expression after treatment of HepG2 cells with lectin-loaded chitosan-TPP nanoparticles. The preliminary findings of our study highlighted that lectin protein-loaded chitosan-TPP nanoparticles could be a promising anticancer agent.

Evaluation of new environmental friendly particulate soil fertilizers based on agroindustry wastes biopolymers and sugarcane vinasse

This study evaluated the physicochemical and morphological properties of pectin and chitosan particles combined with sugarcane vinasse for soil fertilization applications. Particles were obtained by adding the biopolymeric solutions (pectin or chitosan solution) dropwise into the crosslinking solutions (calcium chloride 1% in ethanolic solution or tripolyphosphate 5% aqueous solution) followed by drying. Vinasse enhanced pectin gel stability improving pectin/vinasse particle properties. Physicochemical characterization indicated that vinasse nutrients were properly incorporated in both pectin and chitosan matrices. Particles showed spherical shape, with an average diameter of 3 and 2 mm for the pectin and chitosan particles with vinasse, respectively. Chitosan particles, compared to pectin, showed lower swelling capacity and solubility and higher mechanical resistance indicating a denser and more compact polymer network. Both particles were able to hinder water evaporation rates from sandy soil under water stress conditions. Biobased particles with vinasse added show potential to be applied as soil fertilizer representing an alternative to use and disposal of this expressive wastewater from sugar and alcohol industries.

Marine Polysaccharides in Pharmaceutical Applications: Fucoidan and Chitosan as Key Players in the Drug Delivery Match Field

The use of marine-origin polysaccharides has increased in recent research because they are abundant, cheap, biocompatible, and biodegradable. These features motivate their application in nanotechnology as drug delivery systems; in tissue engineering, cancer therapy, or wound dressing; in biosensors; and even water treatment. Given the physicochemical and bioactive properties of fucoidan and chitosan, a wide range of nanostructures has been developed with these polysaccharides per se and in combination. This review provides an outline of these marine polysaccharides, including their sources, chemical structure, biological properties, and nanomedicine applications; their combination as nanoparticles with descriptions of the most commonly used production methods; and their physicochemical and biological properties applied to the design of nanoparticles to deliver several classes of compounds. A final section gives a brief overview of some biomedical applications of fucoidan and chitosan for tissue engineering and wound healing.

Encapsulation of ciprofloxacin within modified xanthan gum- chitosan based hydrogel for drug delivery

The aim of the present work was to investigate the preparation of polyelectrolyte hydrogel as potential drug carrier for antibacterial Ciprofloxacin drug (CFX), intended for controlled release formulation. Hydrogel of N-trimehtyl chitosan (TMC)/sodium carboxymethyl xanthan gum (CMXG) was prepared and ciprofloxacin was employed as a model drug to investigate the loading and release performance of the prepared hydrogel. FTIR, DSC, TGA and SEM analysis were used to characterize the TMC/CMXG hydrogel and its CFX loaded hydrogel. The results showed that the ciprofloxacin was successfully incorporated and released from the prepared hydrogel without the loss of structural integrity or the change in its functionality. The encapsulation efficiency of CFX within the prepared hydrogel was found to be increased with increasing the concentration of drug reaching about 93.8 ± 2.1% with concentration of CFX 250 µg/ml. It was shown also that the drug is entrapped within the gel without significant interaction as confirmed from FTIR spectra and DSC analysis. In vitro release study in phosphate buffer saline (PBS), indicated the steady rise in cumulative drug release with the highest release amount, reaching about 96.1 ± 1.8% up to 150 min, whereby the gel with high drug loading efficiency (3.52 ± 0.07%) displayed faster and higher release rate than that of gel containing a smaller amount of drug (0.44 ± 0.01%). The release kinetics of loaded drug followed zero-order kinetics. CFX drug loaded hydrogel showed high activity against the gram positive and gram negative bacterial strains due to the successful released of CFX from the CFX loaded hydrogel into the tested bacterial strains with the highest diameter of inhibition zone against Escherichia coli (67.0 ± 1.0) as compared to reference antibiotic, Gentamicin (28 ± 0.5). Cytotoxicity of the prepared hydrogel was examined in vitro using lung human normal cell lines and showed the highest cell viability (97 ± 0.5%) at concentration up to 50 µg/ml. Consequently, TMC/CMXG hydrogel can be proposed as new controlled release drug delivery system.

pH-Responsive carriers for oral drug delivery: challenges and opportunities of current platforms

Oral administration is a desirable alternative of parenteral administration due to the convenience and increased compliance to patients, especially for chronic diseases that require frequent administration. The oral drug delivery is a dynamic research field despite the numerous challenges limiting their effective delivery, such as enzyme degradation, hydrolysis and low permeability of intestinal epithelium in the gastrointestinal (GI) tract. pH-Responsive carriers offer excellent potential as oral therapeutic systems due to enhancing the stability of drug delivery in stomach and achieving controlled release in intestines. This review provides a wide perspective on current status of pH-responsive oral drug delivery systems prepared mainly with organic polymers or inorganic materials, including the strategies used to overcome GI barriers, the challenges in their development and future prospects, with focus on technology trends to improve the bioavailability of orally delivered drugs, the mechanisms of drug release from pH-responsive oral formulations, and their application for drug delivery, such as protein and peptide therapeutics, vaccination, inflammatory bowel disease (IBD) and bacterial infections.

Biomimetic multi-layered hollow chitosan–tripolyphosphate rod with excellent mechanical performance

Design of hollow and multi-layered features in chitosan–tripolyphosphate rod and the resulting excellent mechanical performance.

Preparation and nanoencapsulation of l-asparaginase II in chitosan-tripolyphosphate nanoparticles and in vitro release study

This paper describes the production, purification, and immobilization of l-asparaginase II (ASNase II) in chitosan nanoparticles (CSNPs). ASNase II is an effective antineoplastic agent, used in the acute lymphoblastic leukemia chemotherapy. Cloned ASNase II gene (ansB) in pAED4 plasmid was transformed into Escherichia coli BL21pLysS (DE3) competent cells and expressed under optimal conditions. The lyophilized enzyme was loaded into CSNPs by ionotropic gelation method. In order to get optimal entrapment efficiency, CSNP preparation, chitosan/tripolyphosphate (CS/TPP) ratio, and protein loading were investigated. ASNase II loading into CSNPs was confirmed by Fourier transform infrared (FTIR) spectroscopy, and morphological observation was carried out by transmission electron microscopy. Three absolute CS/TPP ratios were studied. Entrapment efficiency and loading capacity increased with increasing CS and TPP concentration. The best ratio was applied for obtaining optimal ASNase II-loaded CSNPs with the highest entrapment efficiency. Size, zeta potential, entrapment efficiency, and loading capacity of the optimal ASNase II-CSNPs were 340 ± 12 nm, 21.2 ± 3 mV, 76.2% and 47.6%, respectively. The immobilized enzyme showed an increased in vitro half-life in comparison with the free enzyme. The pH and thermostability of the immobilized enzyme was comparable with the free enzyme. This study leads to a better understanding of how to prepare CSNPs, how to achieve high encapsulation efficiency for a high molecular weight protein, and how to prolong the release of protein from CSNPs. A conceptual understanding of biological responses to ASNase II-loaded CSNPs is needed for the development of novel methods of drug delivery.

Insight on the formation of chitosan nanoparticles through ionotropic gelation with tripolyphosphate

This work reports details pertaining to the formation of chitosan nanoparticles that we prepare by the ionic gelation method. The molecular interactions of the ionic cross-linking of chitosan with tripolyphosphate have been investigated and elucidated by means of all-electron density functional theory. Solvent effects have been taken into account using implicit models. We have identified primary-interaction ionic cross-linking configurations that we define as H-link, T-link, and M-link, and we have quantified the corresponding interaction energies. H-links, which display high interaction energies and are also spatially broadly accessible, are the most probable cross-linking configurations. At close range, proton transfer has been identified, with maximum interaction energies ranging from 12.3 up to 68.3 kcal/mol depending on the protonation of the tripolyphosphate polyanion and the relative coordination of chitosan with tripolyphosphate. On the basis of our results for the linking types (interaction energies and torsion bias), we propose a simple mechanism for their impact on the chitosan/TPP nanoparticle formation process. We introduce the β ratio, which is derived from the commonly used α ratio but is more fundamental since it additionally takes into account structural details of the oligomers.

Mobilization of mesenchymal stem cells by stromal cell-derived factor-1 released from chitosan/tripolyphosphate/fucoidan nanoparticles

Stromal cell-derived factor 1 (SDF-1) is an important chemokine in stem cell mobilization, and plays a critical role in the biological and physiological functions of mesenchymal stem cells (MSC). However, the use of SDF-1 in tissue regeneration is limited by two drawbacks, which are its short half-life and ready degradation by enzymes. This study investigates the release of SDF-1 from chitosan-based nanoparticles (NP) and evaluates the effect of released SDF-1 on the migration of MSC. Among the prepared chitosan-based NP a chitosan/tripolyphosphate/fucoidan (CS/TPP/F) NP is the most effective carrier for SDF-1 release. CS/TPP/F NP are spherical and effectively encapsulate SDF-1. The CS/TPP/F NP protected SDF-1 against proteolysis and heat treatment and controlled its release for up to 7 days. The concentration of released SDF-1 reached 23 ng ml(-1). According to in vitro experiments on cells the released SDF-1 retained its mitogenic activity, promoted the migration of MSC and enhanced PI3K expression. Biocompatible CS/TPP/F NP may be effective as carriers for the delivery and controlled release of SDF-1 to mobilize stem cells in tissue engineering applications.