Ionotropic Gelation of Chitosan Flat Structures and Potential Applications

Chitosan-encapsulated bacteriophage cocktail as promising oral delivery system to surpass gastrointestinal infection caused by Klebsiella aerogenes

Bacteriophages hold promise for combating pathogenic bacteria in the human intestinal tract, but their therapeutic potential is limited by harsh stomach conditions, including low pH and digestive enzymes. This study aimed to develop a natural protective mechanism for orally administering phages to treat gastric infections caused by Klebsiella aerogenes. Results revealed that free phages became inactive at pH 3 without protective measures. Encapsulation within sodium alginate (SA) alone (Bead 1) enabled phage survival at pH 2.5. More notably, Bead 2, consisting of a phage cocktail encapsulated in a chitosan-SA matrix supplemented with honey, casein, and gelatin, demonstrated enhanced survival even at pH 1.5. Phage titers in Bead 2 exhibited a controlled release, with near-complete discharge over 5 h in a simulated intestinal solution at 37 °C, ensuring effective delivery to the intestinal environment. Exposure of K. aerogenes to Bead 2 under these conditions resulted in a maximum reduction of 6.2 log10 CFU/mL, compared to maximal reductions of 2.8 log10 CFU/mL for Bead 1 and free phages. This optimized bead-encapsulation method provides a viable, efficient, and cost-effective strategy for delivering functional phages to specifically target intestinal bacteria.

Exploring chitosan nanoparticles for enhanced therapy in neurological disorders: a comprehensive review

Chitosan nanoparticles have emerged as a promising therapeutic platform for treating neurological disorders due to their biocompatibility, biodegradability, and ease of functionalization. One of the significant challenges in treating neurological conditions is overcoming the blood-brain barrier (BBB), which restricts the effective delivery of therapeutic agents to the brain. Addressing this barrier is crucial for the successful treatment of various neurological diseases, including Alzheimer's disease, Parkinson's disease, epilepsy, migraine, psychotic disorders, and brain tumors. Chitosan nanoparticles offer several advantages: they enhance drug absorption, protect drugs from degradation, and enable targeted delivery. These properties open new possibilities for non-invasive therapies for neurological conditions. Numerous studies have highlighted the neuroprotective potential of chitosan nanoparticles, demonstrating improved outcomes in animal models of neurodegeneration and neuroinflammation. Additionally, surface modifications of these nanoparticles allow for the attachment of specific ligands or molecules, enhancing the precision of drug delivery to neuronal cells. Despite these advancements, several challenges persist in the clinical translation of chitosan nanoparticles. Issues such as large-scale production, regulatory hurdles, and the need for further research into long-term safety must be addressed. This review explores recent advancements in the use of chitosan nanoparticles for managing neurological disorders and outlines potential future directions in this rapidly evolving field of research.

Formulation of Ethyl Cellulose Nanoparticles Encapsulated with Osthole Provides Long-Lasting Plant Protection against a Major Pest Mite

The broader use of botanical pesticides has been limited by shorter residual activity on plants, slower onset of action, and higher costs compared with conventional pesticides. These challenges could be overcome by the development of simple, cost-effective, and long-lasting preventive nanocomposites for botanical pesticides. In this study, we successfully developed a low-cost ethyl cellulose (EC)-based delivery system for the botanical pesticide osthole (OST), designed to provide extended preventive protection against Tetranychus urticae infestations. A comparative analysis of the three nanocomposites (graphene oxide (GO)-OST, EC-OST, and chitosan (CS)-OST) revealed that EC-OST exhibited superior thermal stability, UV resistance, controlled release of the OST payload, and strong acaricidal activity. The degradation of OST on leaf surfaces was reduced by encapsulation in EC, while its penetration into plant tissues was improved. When EC-OST was applied to leaves, an increase in T. urticae mortality, a reduction in reproduction and egg adhesion, and impairment of feeding behavior through extended searching and feeding times were observed. The peak occurrence of T. urticae infestation was delayed by 10 days following the preventive application of EC-OST, reducing plant damage and protecting the plants for more than 20 days. This nanoinsecticide allows for low-frequency OST application, reducing farmers' production costs, and increasing profitability, thereby offering great potential for promoting the use of botanical pesticides in plant protection.

Exploring the Potential of Chitosan-Phytochemical Composites in Preventing the Contamination of Antibiotic-Resistant Bacteria on Food Surfaces: A Review

The escalating presence of antibiotic-resistant bacteria (ARB) in food systems presents a pressing challenge, particularly in preventing contamination and ensuring food safety. Traditional sanitation methods, such as cooking and chemical disinfectants, provide effective means to reduce ARB, yet there is a growing need for additional preventive measures directly on food surfaces. This review explores the potential of chitosan-phytochemical composites (CPCs) as surface coatings to prevent the initial contamination of food by ARB, thereby offering a novel complementary approach to conventional food safety practices. Chitosan, combined with active plant-derived metabolites (phytochemicals), forms composites with notable antibacterial and antioxidant properties that enhance its protective effects. We examine CPC synthesis methodologies, including chemical modifications, free radical-induced grafting, and enzyme-mediated techniques, which enhance the stability and activity of CPCs against ARB. Highlighting recent findings on CPCs' antibacterial efficacy through minimum inhibitory concentrations (MIC) and zones of inhibition, this review underscores its potential to reduce ARB contamination risks on food surfaces, particularly in seafood, meat, and postharvest products. The insights provided here aim to encourage future strategies leveraging CPCs as a preventative surface treatment to mitigate ARB in food production and processing environments.

Potential of Cricket Chitosan for Nanoparticle Development Through Ionotropic Gelation: Novel Source for Cosmeceutical Delivery Systems

BACKGROUND/OBJECTIVES

Crickets are recognized as an alternative source of chitosan. This study aimed to assess the potential of cricket-derived chitosan as a natural source to develop chitosan nanoparticles (CNPs).

METHODS

Chitosan were isolated from different cricket species, including Gryllus bimaculatus, Teleogryllus mitratus, and Acheta domesticus. The isolated chitosan were characterized by their functional groups, crystallographic and thermal properties, molecular structure, morphology, water solubility, molecular weight, binding capacity, irritation potential, and cytotoxicity in comparison to commercial shrimp-based chitosan. CNPs were developed through an ionotropic gelation method, followed by the evaluation of particle size, polydispersity index (PDI), and zeta potential.

RESULTS

The findings of this study indicate that chitosan can be successfully isolated from the three cricket species, with yields ranging from 4.35% to 5.22% w/w of the dried material. The characteristics of cricket-based chitosan were similar to those of commercial chitosan, except that the cricket-based chitosan displayed a higher crystallinity and a lower molecular weight. Additionally, CPNs were successfully produced from cricket-based chitosan using sodium citrate as a crosslinking agent. All cricket-based chitosan exhibited no irritation or cytotoxicity. Chitosan derived from A. domesticus however was found to be the most suitable to develop CPNs, as it produced the smallest particle size (522.0 ± 12.1 nm) with a comparatively narrow PDI (0.388 ± 0.026) and an acceptable positive zeta potential (34.2 ± 4.4 mV).

CONCLUSIONS

Cricket-derived chitosan compares favorably with crustacean-derived chitosan and showed potential for a range of applications, including the use as a nanocosmeceutical delivery system in topical and cosmetic formulations.

Ferric ions crosslinked hyaluronic acid beads: potentials for drug delivery use

INTRODUCTION AND PURPOSE

Despite the attractive properties of hyaluronic acid (HA), The preparation of HA beads is still challenging. This article reports the preparation of pH-sensitive gel HA beads. The ionic gelation method was used to prepare the HA gel beads using ferric ions. This cross-linking type is based on forming coordination bonds, which enhance the mechanical properties of the prepared beads.

METHODS

The developed beads were characterized using Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Scanning electron microscopy (SEM) examined the bead's morphology. Furthermore, the potential of HA gel beads as an oral drug delivery system was investigated using metformin as a hydrophilic model drug. The entrapment efficiency and in vitro, release, and release kinetics were evaluated. The crosslinking density and HA concentration effect on drug release and bead swelling capacity under pH 1.2 and 7.4 were also investigated.

RESULTS

The entrapment efficiency of metformin in HA beads was found to be 79.56 ± 3.89%. FTIR analysis indicated the ionic interaction between ferric ions and the carboxylic groups on the HA molecule. At the same time, there was no substantial interaction between metformin and the polymeric bead. Morphological evaluation and DSC analysis suggested the successful incorporation of metformin within the beads. The in vitro drug release evaluation showed pH-dependent extended release where the release kinetics followed the first-order mathematical model.

CONCLUSIONS

This study provides a value-added formulation with the potential for drug delivery use, which can be further investigated for biomedical applications.

Folate-engineered chitosan nanoparticles: next-generation anticancer nanocarriers

Chitosan nanoparticles (NPs) are well-recognized as promising vehicles for delivering anticancer drugs due to their distinctive characteristics. They have the potential to enclose hydrophobic anticancer molecules, thereby enhancing their solubilities, permeabilities, and bioavailabilities; without the use of surfactant, i.e., through surfactant-free solubilization. This allows for higher drug concentrations at the tumor sites, prevents excessive toxicity imparted by surfactants, and could circumvent drug resistance. Moreover, biomedical engineers and formulation scientists can also fabricate chitosan NPs to slowly release anticancer agents. This keeps the drugs at the tumor site longer, makes therapy more effective, and lowers the frequency of dosing. Notably, some types of cancer cells (fallopian tube, epithelial tumors of the ovary, and primary peritoneum; lung, kidney, ependymal brain, uterus, breast, colon, and malignant pleural mesothelioma) have overexpression of folate receptors (FRs) on their outer surface, which lets folate-drug conjugate-incorporated NPs to target and kill them more effectively. Strikingly, there is evidence suggesting that the excessively produced FR&αgr (isoforms of the FR) stays consistent throughout treatment in ovarian and endometrial cancer, indicating resistance to conventional treatment; and in this regard, folate-anchored chitosan NPs can overcome it and improve the therapeutic outcomes. Interestingly, overly expressed FRs are present only in certain tumor types, which makes them a promising biomarker for predicting the effectiveness of FR-targeted therapy. On the other hand, the folate-modified chitosan NPs can also enhance the oral absorption of medicines, especially anticancer drugs, and pave the way for effective and long-term low-dose oral metronomic scheduling of poorly soluble and permeable drugs. In this review, we talked briefly about the techniques used to create, characterize, and tailor chitosan-based NPs; and delved deeper into the potential applications of folate-engineered chitosan NPs in treating various cancer types.

Recent advances on chitosan/hyaluronic acid-based stimuli-responsive hydrogels and composites for cancer treatment: A comprehensive review

Cancer, as leading cause of death, has a high rate of mortality worldwide. Although there is a wide variety of conventional approaches for the treatment of cancer (such as surgery and chemotherapy), they have considerable drawbacks in terms of practicality, treatment efficiency, and cost-effectiveness. Therefore, there is a fundamental requirement for the development of safe and efficient treatment modalities based on breakthrough technologies to suppress cancer. Chitosan (CS) and hyaluronic acid (HA) polysaccharides, as FDA-approved biomaterials for some biomedical applications, are potential biopolymers for the efficient treatment of cancer. CS and HA have high biocompatibility, bioavailability, biodegradability, and immunomodulatory function which guarantee their safety and non-toxicity. CS-/HA-based hydrogels (HGs)/composites stand out for their potential anticancer function, versatile preparation and modification, ease of administration, controlled/sustained drug release, and active and passive drug internalization into target cells which is crucial for efficient treatment of cancer compared with conventional treatment approaches. These HGs/composites can respond to external (magnetic, ultrasound, light, and thermal) and internal (pH, enzyme, redox, and ROS) stimuli as well which further paves the way to their manipulation, targeted drug delivery, practicality, and efficient treatment. The above-mentioned properties of CS-/HA-based HGs/composites are unique and practical in cancer treatment which can ignore the deficiencies of conventional approaches. The present manuscript comprehensively highlights the advances in the practical application of stimuli-responsive HGs/composites based on CS/HA polysaccharides.

Chitosan: An overview of biological activities, derivatives, properties, and current advancements in biomedical applications

The second and most often utilized natural polymer is chitosan (CS), a naturally existing amino polysaccharide that is produced by deacetylating chitin. Numerous applications have been the subject of in-depth investigation due to its non-hazardous, biologically compatible, and biodegradable qualities. Chitosan's characteristics, such as mucoadhesion, improved permeability, controlled release of drugs, in situ gelation process, and antibacterial activity, depend on its amino (-NH2) and hydroxyl groups (-OH). This study examines the latest findings in chitosan research, including its characteristics, derivatives, preliminary research, toxic effects, pharmaceutical kinetics and chitosan nanoparticles (CS-NPs) based for non-parenteral delivery of drugs. Chitosan and its derivatives have a wide range of physical and chemical properties that make them highly promising for use in the medicinal and pharmaceutical industries. The characteristics and biological activities of chitosan and its derivative-based nanomaterials for the delivery of drugs, therapeutic gene transfer, delivery of vaccine, engineering tissues, evaluations, and other applications in medicine are highlighted in detail in the current review. Together with the techniques for binding medications to nanoparticles, the application of the nanoparticles was also dictated by their physical properties that were classified and specified. The most recent research investigations on delivery of drugs chitosan nanoparticle-based medication delivery methods applied topically, through the skin, and through the eyes were considered.

Composite Microgels Loaded with Doxorubicin-Conjugated Amine-Functionalized Zinc Ferrite Nanoparticles for Stimuli-Responsive Sustained Drug Release

Purpose

The purpose of this study is to address the need for efficient drug delivery with high drug encapsulation efficiency and sustained drug release. We aim to create nanoparticle-loaded microgels for potential applications in treatment development.

Methods

We adopted the process of ionic gelation to generate microgels from sodium alginate and carboxymethyl cellulose. These microgels were loaded with doxorubicin-conjugated amine-functionalized zinc ferrite nanoparticles (AZnFe-NPs). The systems were characterized using various techniques. Toxicity was evaluated in MCF-7 cells. In vitro release studies were conducted at different pH levels at 37 oC, with the drug release kinetics being analyzed using various models.

Results

The drug encapsulation efficiency of the created carriers was as high as 70%. The nanoparticle-loaded microgels exhibited pH-responsive behavior and sustained drug release. Drug release from them was mediated via a non-Fickian type of diffusion.

Conclusion

Given their high drug encapsulation efficiency, sustained drug release and pH-responsiveness, our nanoparticle-loaded microgels show promise as smart carriers for future treatment applications. Further development and research can significantly benefit the field of drug delivery and treatment development.

Preparing high-performance microspheres based on the chitosan-assisted dispersion of reduced graphene oxide in aqueous solution for bilirubin removal

The removal of excess bilirubin from blood is of great clinical importance. Reduced graphene oxide (rGO) is often used to efficiently remove bilirubin. However, thin rGO pieces tend to aggregate in the aqueous phase because they are hydrophobic. In this context, we propose an effective strategy based on the chitosan-assisted (CS-assisted) dispersion of rGO to produce high-performance bilirubin-adsorbing microspheres. CS possesses a hydrophobic CH structure, which offers strong hydrophobic interactions with rGO that assist its dispersion, and the large number of hydrophilic sites of CS increases the hydrophilicity of rGO. CS serves as a dispersant in a surfactant-like manner to achieve a homogeneous and stable CS/rGO dispersion by simply and gently stirring CS and rGO in a LiOH/KOH/urea/H2O system. Subsequently, CS/rGO hybrid microspheres were prepared by emulsification. CS ensures blood compatibility as a base material, and the entrapped rGO contributes to mechanical strength and a high adsorption capacity. The CS/rGO microspheres exhibited a high bilirubin adsorption capacity (215.56 mg/g), which is significantly higher than those of the rGO and CS microspheres. The determined mass-transfer factors revealed that the rich pores of the CS/rGO microspheres promote mass transfer during bilirubin adsorption (equilibrium is almost achieved within 30 min). The CS/rGO microspheres are promising candidates for bilirubin removal owing to a combination of high strength, blood compatibility, and high adsorption capacity.

Synthesis and characterization of functional calcium-phosphate-chitosan adsorbents for fluoride removal from water

Functional calcium-phosphate-chitosan adsorbents for fluoride (F-) removal from water with different proportions of calcium (0.7 or 1.4 % w/v) were synthesized by: i) ionotropic gelation technique followed by drying in a convection oven (IGA) or freeze drying (FDA); ii) freeze-gelation followed by drying in a convection oven (FGA). Adsorbents were analyzed by SEM-EDX and FTIR- ATR. F- removal percentages higher than 45 % were obtained with calcium-phosphate-chitosan adsorbents for an initial F- concentration of 9.6 mg L-1. Optimal conditions for F- removal were attained, using calcium-phosphate- chitosan adsorbents synthesized by ionotropic gelation with 0.7 % of Ca (IGA0.7). Under these conditions, initial F- concentration of 5 mg L-1, was reduced below the maximum limit of 1.5 mg L-1 established by WHO. Regeneration of IGA0.7 was achieved in acid media. The performance of IGA0.7 was slightly reduced in the presence of coexisting anions (nitrate, carbonate, arsenate). Adsorption kinetics was represented satisfactorily by the pseudo-second order equation; Langmuir isotherm provided the best fit to the equilibrium data and IGA0.7 exhibited a maximum F- adsorption capacity qL = 132.25 mg g-1. IGA0.7 particles were characterized by thermogravimetry coupled to FTIR, XRD, XPS and SEM-EDX. The calcium-phosphate-chitosan adsorbents constitute a suitable and emerging material for water defluorination.

Nanocarriers for the Delivery of Quercetin to Inhibit the UV-Induced Aggregation of γD-Crystallin

Due to gradual environmental changes like ozone layer depletion and global warming, human eyes are exposed to UV light. Exposure to UV light can be a cause of cataracts, one of the ocular diseases that may cause vision impairment. To date, lens replacement has been the only treatment available for cataracts. In our present study, we carried out an extensive examination of polyphenols as inhibitors for UV-induced aggregation of γD-crystallin. On exposure to UV-C light, γD-crystallin forms fibrils instead of amorphous aggregates. Various polyphenols were tested as inhibitors; out of them, quercetin, baicalein, and caffeic acid were found to be effective. As polyphenols are insoluble in water, nanoencapsulation was used to enhance their bioavailability. CS-TPP and CS-PLGA encapsulating systems were considered, as they form biodegradable nanocapsules. Out of three polyphenols (quercetin, baicalein, and caffeic acid), quercetin forms nanocarriers of smaller sizes, a must for crossing the retinal barrier. Quercetin nanocarriers were considered an effective system that could be used for therapeutic applications. For these nanocarriers, encapsulation efficiency and polyphenol release kinetics were studied. CS-PLGA NPs were found to have a better loading efficiency for quercetin than CS-TPP NPs.

A review of chitosan nanoparticles: Nature's gift for transforming agriculture through smart and effective delivery mechanisms

Chitosan nanoparticles (CNPs) have emerged as a promising tool in agricultural advancements due to their unique properties including, biocompatability, biodegradability, non-toxicity and remarkable versatility. These inherent properties along with their antimicrobial, antioxidant and eliciting activities enable CNPs to play an important role in increasing agricultural productivity, enhancing nutrient absorption and improving pest management strategies. Furthermore, the nano-formulation of chitosan have the ability to encapsulate various agricultural amendments, enabling the controlled release of pesticides, fertilizers, plant growth promoters and biocontrol agents, thus offering precise and targeted delivery mechanisms for enhanced efficiency. This review provides a comprehensive analysis of the latest research and developments in the use of CNPs for enhancing agricultural practices through smart and effective delivery mechanisms. It discusses the synthesis methods, physicochemical properties, and their role in enhancing seed germination and plant growth, crop protection against biotic and abiotic stresses, improving soil quality and reducing the environmental pollution and delivery of agricultural amendments. Furthermore, the potential environmental benefits and future directions for integrating CNPs into sustainable agricultural systems are explored. This review aims to shed light on the transformative potential of chitosan nanoparticles as nature's gift for revolutionizing agriculture and fostering eco-friendly farming practices.

Exploring modified chitosan-based gene delivery technologies for therapeutic advancements

One of the critical steps in gene therapy is the successful delivery of the genes. Immunogenicity and toxicity are major issues for viral gene delivery systems. Thus, non-viral vectors are explored. A cationic polysaccharide like chitosan could be used as a nonviral gene delivery vector owing to its significant interaction with negatively charged nucleic acid and biomembrane, providing effective cellular uptake. However, the native chitosan has issues of targetability, unpacking ability, and solubility along with poor buffer capability, hence requiring modifications for effective use in gene delivery. Modified chitosan has shown that the "proton sponge effect" involved in buffering the endosomal pH results in osmotic swelling owing to the accumulation of a greater amount of proton and chloride along with water. The major challenges include limited exploration of chitosan as a gene carrier, the availability of high-purity chitosan for toxicity reduction, and its immunogenicity. The genetic drugs are in their infancy phase and require further exploration for effective delivery of nucleic acid molecules as FDA-approved marketed formulations soon.

The Fabrication of Polymer-Based Curcumin-Loaded Formulation as a Drug Delivery System: An Updated Review from 2017 to the Present

Turmeric contains curcumin, a naturally occurring compound with noted anti-inflammatory and antioxidant properties that may help fight cancer. Curcumin is readily available, nontoxic, and inexpensive. At high doses, it has minimal side effects, suggesting it is safe for human use. However, curcumin has extremely poor bioavailability and biodistribution, which further hamper its clinical applications. It is commonly administered through oral and transdermal routes in different forms, where the particle size is one of the most common barriers that decreases its absorption through biological membranes on the targeted sites and limits its clinical effectiveness. There are many studies ongoing to overcome this problem. All of this motivated us to conduct this review that discusses the fabrication of polymer-based curcumin-loaded formulation as an advanced drug delivery system and addresses different approaches to overcoming the existing barriers and improving its bioavailability and biodistribution to enhance the therapeutic effects against cancer and other diseases.

Comparison of the protective effects of CS/TPP and CS/HPMCP nanoparticles containing berberine in ethanol-induced hepatotoxicity in rat

BACKGROUND

Alcoholic liver disease (ALD) is a globally critical condition with no available efficient treatments.

METHODS

Herein, we generated chitosan (CS) nanoparticles cross-linked with two different agents, hydroxypropyl methylcellulose phthalate (HPMCP; termed as CS/HPMCP) and tripolyphosphate (TPP; termed as CS/TPP), and loaded them with berberine (BBr; referred to as CS/HPMCP/BBr and CS/TPP/BBr, respectively). Alongside the encapsulation efficiency (EE) and loading capacity (LC), the releasing activity of the nanoparticles was also measured in stimulated gastric fluid (SGF) and stimulated intestinal fluid (SIF) conditions. The effects of the prepared nanoparticles on the viability of mesenchymal stem cells (MSCs) were also evaluated. Ultimately, the protective effects of the nanoparticles were investigated in ALD mouse models.

RESULTS

SEM images demonstrated that CS/HPMCP and CS/TPP nanoparticles had an average size of 235.5 ± 42 and 172 ± 21 nm, respectively. The LC and EE for CS/HPMCP/BBr were calculated as 79.78% and 75.79%, respectively; while the LC and EE for CS/TPP/BBr were 84.26% and 80.05%, respectively. pH was a determining factor for releasing BBr from CS/HPMCP nanoparticles as a higher cargo-releasing rate was observed in a less acidic environment. Both the BBr-loaded nanoparticles increased the viability of MSCs in comparison with their BBr-free counterparts. In vivo results demonstrated CS/HPMCP/BBr and CS/TPP/BBr nanoparticles protected enzymatic liver functionality against ethanol-induced damage. They also prevented histopathological ethanol-induced damage.

CONCLUSIONS

Crosslinking CS nanoparticles with HPMCP can mediate controlled drug release in the intestine improving the bioavailability of BBr.

Chitosan-Se Engineered Nanomaterial Mitigates Salt Stress in Plants by Scavenging Reactive Oxygen Species

Soil salinity seriously hinders the sustainable development of green agriculture. The emergence of engineered nanomaterials has revolutionized agricultural research, providing a new means to overcome the limitations associated with current abiotic stress management and achieve highly productive agriculture. Herein, we synthesized a brand-new engineered nanomaterial (Cs-Se NMs) through the Schiff base reaction of oxidized chitosan with selenocystamine hydrochloride to alleviate salt stress in plants. After the addition of 300 mg/L Cs-Se NMs, the activity of superoxide dismutase, catalase, and peroxidase in rice shoots increased to 3.19, 1.79, and 1.85 times those observed in the NaCl group, respectively. Meanwhile, the MDA levels decreased by 63.9%. Notably, Cs-Se NMs also raised the transcription of genes correlated with the oxidative stress response and MAPK signaling in the transcriptomic analysis. In addition, Cs-Se NMs augmented the abundance and variety of rhizobacteria and remodeled the microbial community structure. These results provide insights into applying engineered nanomaterials in sustainable agriculture.

Scalable production of chitosan sub-micron particles by membrane ionotropic gelation process

Ionotropic gelation (IG) is a highly attractive method for the synthesis of natural water-soluble polymeric nanoparticles (NPs) and sub-micron particles (sMP) due to its relatively simple procedure and the absence of organic solvents. The method involves the electrostatic interaction between two ionic species of opposite charge. Although it is well studied at the laboratory scale, the difficulty to achieve size control in conventional bench-top process is actually a critical aspect of the technology. The aim of this work is to study the membrane dispersion technology in combination with IG as a suitable scalable method for the production of chitosan sub-micron particles (CS-sMPs). The two phases, one containing chitosan (CS) and the other containing sodium tripolyphosphate (TPP), were put in contact using a tubular hydrophobic glass membrane with a pore diameter of 1 μm. TPP (dispersed phase) was permeated through the membrane pores into the lumen side along which the CS solution (the continuous phase) flowed in batch recirculation or continuous single-pass operation mode. The influence of chemical variables (i.e. pH, concentration and mass ratio of polyelectrolyte species, emulsifier) and fluid-dynamic parameters (i.e. polyelectrolyte solution flow rate and their relative mass ratio) was studied to precisely tune the size of CS-Ps.

Evaluation of curcumin-loaded chitosan nanoparticles for wound healing activity

Background and purpose

Wound healing is a biological process that can be difficult to manage clinically. In skin wound healing, the interaction of many cells, growth factors, and cytokines reveals an outstanding biological function mechanism. Wound healing that occurs naturally restores tissue integrity, however, it is usually restricted to wound repair. Curcumin synthesised in a chitosan matrix can be used to heal skin sores.

Experimental approach

The ionotropic gelation procedure required crosslinking chitosan with a tripolyphosphate (TPP) crosslinker to generate curcumin nanoparticles encapsulated in chitosan.

Key results

The nanoparticles were between 200 and 400 nm in size, with a strong positive surface charge and good entrapment efficacy, according to SEM and TEM investigations. Curcumin and chitosan compatibility was investigated using FTIR spectroscopy. All batches showed consistent drug release, with the F5 batch having the highest curcumin release, at 75% after 16 hours. On L929 cells, scratch assays were utilised to assess wound healing. Wound closure with widths of 59 and 65 mm with curcumin and 45 and 78 mm with curcumin-loaded chitosan nanoparticles was seen after 24 and 48 hours of examination.

Conclusions

According to the findings, prepared curcumin chitosan nanoparticles are beneficial in healing skin damage.

Chitosan based sorafenib tosylate loaded magnetic nanoparticles: Formulation and in-vitro characterization

Biocompatible magnetic nanoparticles are used for various biomedical applications. This study reported the development of nanoparticles with magnetic properties by embedding magnetite particles in the drug-loaded, crosslinked matrix of chitosan. Sorafenib tosylate-loaded magnetic nanoparticles were prepared by a modified ionic-gelation method. Particle size, zeta potential, polydispersity index, and entrapment efficiency of nanoparticles were in the range of 95.6 ± 3.4 nm to 440.9 ± 7.3 nm, 12.8 ± 0.8 mV to 27.3 ± 1.1 mV, 0.289 ± 0.011 to 0.571 ± 0.011, and 54.36 ± 1.26 % to 79.67 ± 1.40 %, respectively. The XRD spectrum of formulation CMP-5 confirmed the amorphous nature of the loaded drug in nanoparticles. TEM image confirmed the spherical shape of nanoparticles. Atomic force microscopic image of formulation CMP-5 indicated a mean surface roughness of 10.3597 nm. The magnetization saturation of formulation CMP-5 was 24.74 emu/g. Electron paramagnetic resonance spectroscopy revealed that formulation CMP-5's g-Lande's factor was 4.27, which was extremely near to the 4.30 (usual for Fe³⁺ ions). Residual paramagnetic Fe³⁺ ions may be responsible for paramagnetic origin. The data suggests superparamagnetic nature of particles. Formulations released 28.66 ± 1.22 % to 53.24 ± 1.95 % and 70.13 ± 1.72 % to 92.48 ± 1.32 % of the loaded drug after 24 h in pH 6.8 and pH 1.2, respectively. The IC₅₀ value of formulation CMP-5 was 54.75 μg/mL in HepG2 (human hepatocellular carcinoma cell lines).

Recent progressions in biomedical and pharmaceutical applications of chitosan nanoparticles: A comprehensive review

Nowadays, the most common approaches in the prognosis, diagnosis, and treatment of diseases are along with undeniable limitations. Thus, the ever-increasing need for using biocompatible natural materials and novel practical modalities is required. Applying biomaterials, such as chitosan nanoparticles (CS NPs: FDA-approved long-chain polymer of N-acetyl-glucosamine and D-glucosamine for some pharmaceutical applications), can serve as an appropriate alternative to overcome these limitations. Recently, the biomedical applications of CS NPs have extensively been investigated. These NPs and their derivatives can not only prepare through different physical and chemical approaches but also modify with various molecules and bioactive materials. The potential properties of CS NPs, such as biocompatibility, biodegradability, serum stability, solubility, non-immunogenicity, anti-inflammatory properties, appropriate pharmacokinetics and pharmacodynamics, and so forth, have made them excellent candidates for biomedical applications. Therefore, CS NPs have efficiently applied for various biomedical applications, like regenerative medicine and tissue engineering, biosensors for the detection of microorganisms, and drug delivery systems (DDS) for the suppression of diseases. These NPs possess a high level of biosafety. In summary, CS NPs have the potential ability for biomedical and clinical applications, and it would be remarkably beneficial to develop new generations of CS-based material for the future of medicine.

Effects of Pork Backfat Replacement with Emulsion Gels Formulated with a Mixture of Olive, Chia and Algae Oils on the Quality Attributes of Pork Patties

This paper reports on the development of new emulsion gels containing a mixture of olive, chia and algae oil emulsified with soy protein isolate and stabilized by two different cold gelling agents, gelatin (EGEL) and chitosan (ECHIT), and to evaluate their potential use as pork backfat replacers in cooked pork patties. Reformulated patties were produced by half and full pork backfat replacement and compared to normal fat patties and reduced fat content patties made by replacing half of the added fat with water. Color parameters, pH and thermal stability of the emulsion gels were determined at processing and after 10 days of refrigerated storage. Proximate composition, fatty acid profile, technological properties and sensory attributes were evaluated after patty processing, while color parameters, pH and lipid oxidation were monitored in patties during 15 days of refrigerated storage (4 °C). Reformulated patties showed significant improvements of the lipid profile (lower saturated fatty acid content and n-6/n-3 ratio and higher long-chain polyunsaturated fatty acid content) as compared to the controls. In terms of technological properties, chitosan was more effective than gelatin as a stabilizer of the emulsion gel. All reformulated patties showed a good evolution of lipid oxidation during storage and acceptable sensory attributes.

Thiolated pectin-chitosan composites: Potential mucoadhesive drug delivery system with selective cytotoxicity towards colorectal cancer

Mucoadhesive drug delivery systems (DDS) may promote safer chemotherapy for colorectal cancer (CRC) by maximizing local drug distribution and residence time. Carbohydrate polymers, e.g. pectin (P) and chitosan (CS), are potential biomaterials for CRC-targeted DDS due to their gelling ability, mucoadhesive property, colonic digestibility, and anticancer activity. Polymer mucoadhesion is augmentable by thiolation, e.g. pectin to thiolated pectin (TP). Meanwhile, P-CS polyelectrolyte complex has been shown to improve structural stability. Herein, we fabricated, characterized, and evaluated 5-fluorouracil-loaded primary DDS combining TP and CS as a composite (TPCF) through triple crosslinking actions (calcium pectinate, polyelectrolyte complex, disulfide). Combination of these crosslinking yields superior mucoadhesion property relative to single- or dual-crosslinked counterparts, with comparable drug release profile and drug compatibility. PCF and TPCF exhibited targeted cytotoxicity towards HT29 CRC cells with milder cytotoxicity towards HEK293 normal cells. In conclusion, TP-CS composites are promising next-generation mucoadhesive and selectively cytotoxic biomaterials for CRC-targeted DDS.

Tumor targeted delivery of mycobacterial adjuvant encapsulated chitosan nanoparticles showed potential anti-cancer activity and immune cell activation in tumor microenvironment

Targeting immunotherapeutics inside the tumor microenvironment (TME) with intact biological activity remains a pressing issue. Mycobacterium indicus pranii (MIP), an approved adjuvant therapy for leprosy has exhibited promising results in clinical trials of lung (NSCLC) and bladder cancer. Whole MIP as well as its cell wall fraction have shown tumor growth suppression and enhanced survival in mice model of melanoma, when administered peritumorally. Clinically, peritumoral delivery remains a procedural limitation. In this study, a tumor targeted delivery system was designed, where chitosan nanoparticles loaded with MIP adjuvants, when administered intravenously showed preferential accumulation within the TME, exploiting the principle of enhanced permeability and retention effect. Bio-distribution studies revealed their highest concentration inside the tumor after 6 h of administration. Interestingly, MIP adjuvant nano-formulations significantly reduced the tumor volume in the treated groups and increased the frequency of activated immune cells inside the TME. For chemoimmunotherapeutics studies, MIP nano-formulation was combined with standard dosage regimen of Paclitaxel. Combined therapy exhibited a further reduction in tumor volume relative to either of the MIP nano formulations. From this study a three-pronged strategy emerged as the underlying mechanism; chitosan and Paclitaxel have shown direct role in tumor cell death and the MIP nano-formulation activates the tumor residing immune cells which ultimately leads to the reduced tumor growth.

Bioactive-loaded nanodelivery systems for the feed and drugs of livestock; purposes, techniques and applications

Advances in animal husbandry and better performance of livestock results in growing demands for feed and its nutrients, bioactive compounds (bioactives), such as vitamins, minerals, proteins, and phenolics, along with drugs/vaccines. To protect the feed bioactives in unintended circumstances, they can be encapsulated to achieve desired efficacy in animal feeding and nanoencapsulation gives more potential for better protection, absorption and targeted delivery of bioactives. This study reviews structures, properties, and methods of nanoencapsulation for animal feedings and relevant drugs. Essential oil (EOs) and plant extracts are mostly encapsulated bioactives and phytochemicals for poultry diets and chitosan is found as most effective nanocarrier to load EOs and plant extracts. Nanoparticles (NPs) and nanocapsules are frequently studied nanocarriers, which are mostly processed by using the ionotropic/ionic gelation. Nanofibers, nanohydrogels and nanoemulsions are not found yet for their application in feed bioactives. These nanocarriers can have an improved protection, stability, and controlled release of feed bioactives which benefits to additional nutrition for the growth of livestock regardless of the low stability and water solubility of bioactives. For ruminants' feeds, nano-minerals, vitamins, phytochemicals, essential fatty acids, and drugs are encapsulated by NPs to facilitate the delivery to target organs through direct penetration, to improve their bioavailability, to generate more efficient absorption in cells and tissues, and protect them from rapid degradation. Furthermore, safety and regulatory issues, as well as advantages and disadvantages of nanoencapsulation application in animal feeds are also discussed. The review shows an accurate design of NPs can largely mask safety issues with straightforward approaches and awareness of safety concerns is fundamental for better designing of nanoencapsulation systems and commercialization. This review gives an insight of understanding and potential of nanoencapsulation in ruminants and poultry feedings to obtain a better bioavailability of the nutrients and bioactives with improved safety and awareness for better designing of nanoencapsulating systems.

Chitosan-based scaffolds as drug delivery systems in bone tissue engineering

The bone tissue engineering approach for treating large bone defects becomes necessary when the tissue damage surpasses the threshold of the inherent regenerative ability of the human body. A myriad of natural biodegradable polymers and scaffold fabrication techniques have emerged in the last decade. Chitosan (CS) is especially attractive as a bone scaffold material to support cell attachment and proliferation and mineralization of the bone matrix. The primary amino groups in CS are responsible for properties such as controlled drug release, mucoadhesion, in situ gelation, and transfection. CS-based smart drug delivery scaffolds that respond to environmental stimuli have been reported to have a localized sustained delivery of drugs in the large bone defect area. This review outlines the recent advances in the fabrication of CS-based scaffolds as a pharmaceutical carrier to deliver drugs such as antibiotics, growth factors, nucleic acids, and phenolic compounds for bone tissue regeneration.

Curcumin-Based Nanoformulations: A Promising Adjuvant towards Cancer Treatment

Throughout the United States, cancer remains the second leading cause of death. Traditional treatments induce significant medical toxic effects and unpleasant adverse reactions, making them inappropriate for long-term use. Consequently, anticancer-drug resistance and relapse are frequent in certain situations. Thus, there is an urgent necessity to find effective antitumor medications that are specific and have few adverse consequences. Curcumin is a polyphenol derivative found in the turmeric plant (Curcuma longa L.), and provides chemopreventive, antitumor, chemo-, and radio-sensitizing properties. In this paper, we summarize the new nano-based formulations of polyphenolic curcumin because of the growing interest in its application against cancers and tumors. According to recent studies, the use of nanoparticles can overcome the hydrophobic nature of curcumin, as well as improving its stability and cellular bioavailability in vitro and in vivo. Several strategies for nanocurcumin production have been developed, each with its own set of advantages and unique features. Because the majority of the curcumin-based nanoformulation evidence is still in the conceptual stage, there are still numerous issues impeding the provision of nanocurcumin as a possible therapeutic option. To support the science, further work is necessary to develop curcumin as a viable anti-cancer adjuvant. In this review, we cover the various curcumin nanoformulations and nanocurcumin implications for therapeutic uses for cancer, as well as the current state of clinical studies and patents. We further address the knowledge gaps and future research orientations required to develop curcumin as a feasible treatment candidate.

Development and Evaluation of a Novel Polymer Drug Delivery System Using Cromolyn-Polyamides-Disulfide using Response Surface Design

The aim of this study was to employ nanoparticles as drug carriers. The research involved the design of cromolyn polyamide-disulfide nanocomposites to overcome the problem of frequent cromolyn doses and improve their properties. The cromolyn polyamide-disulfide samples were prepared using several amounts of cromolyn and sodium polyamide-disulfide polymer at different pH values. Analysis of variance (ANOVA) was performed to obtain the significant independent variables affecting the dependent response by using a $P$ value lower than 0.05. The nanocomposites produced were characterized using Fourier transform infrared (FTIR) spectroscopy and in vitro release. An FTIR test was used to evaluate the functional groups of cromolyn in nanocomposites, which indicated that the drug was encapsulated inside the polymer. All data indicated the presence of cromolyn in the nanocomposites. The release profile of nanocomposites was found to be sustained. Therefore, the outcome of this research project could be a starting point for further work to optimize and assess polyamide-disulfide polymers for delivering another drug.

The first selenium containing chitin and chitosan derivatives: Combined synthetic, catalytic and biological studies

Ultrasonic approach to the synthesis of the first selenium-containing derivatives of chitin and chitosan has been developed. The synthetic procedure is simple, provides high yields, does not require harsh conditions, and uses water as the reaction medium. The elaborated chitin and chitosan derivatives and their based nanoparticles are non-toxic and possess high antibacterial and antifungal activity. Their antimicrobial activity exceeds the effect of the classic antibiotics (Ampicillin and Gentamicin) and the antifungal drug Amphotericin B. The obtained selenium-containing cationic chitin and chitosan derivatives exhibit a high transfection activity and are promising gene delivery vectors. Nanoparticles of the synthesized polymers are highly efficient catalysts for the oxidation of 1-phenylethyl alcohol to acetophenone by bromine at room temperature.

Chitosan-Hyaluronan Nanoparticles for Vinblastine Sulfate Delivery: Characterization and Internalization Studies on K-562 Cells

In the present study, we developed chitosan/hyaluronan nanoparticles (CS/HY NPs) for tumor targeting with vinblastine sulfate (VBL), that can be directed to the CD44 transmembrane receptor, over-expressed in cancer cells. NPs were prepared by coating with HY-preformed chitosan/tripolyphosphate (CS/TPP) NPs, or by polyelectrolyte complexation of CS with HY. NPs with a mean hydrodynamic radius (R_H) of 110 nm, 12% polydispersity index and negative zeta potential values were obtained by a direct complexation process. Transmission Electron Microscopy (TEM) images showed spherical NPs with a non-homogeneous matrix, probably due to a random localization of CS and HY interacting chains. The intermolecular interactions occurring between CS and HY upon NPs formation were experimentally evidenced by micro-Raman (µ-Raman) spectroscopy, through the analysis of the spectral changes of characteristic vibrational bands of HY during NP formation, in order to reveal the involvement of specific chemical groups in the process. Optimized NP formulation efficiently encapsulated VBL, producing a drug sustained release for 20 h. In vitro studies demonstrated a fast internalization of labeled CS/HY NPs (within 6 h) on K-562 human myeloid leukemia cells. Pre-saturation of CD44 by free HY produced a slowing-down of NP uptake over 24 h, demonstrating the need of CD44 for the internalization of HY-based NPs.

Current advances in cell therapeutics: A biomacromolecules application perspective

INTRODUCTION

Many chronic diseases have evolved and to circumvent the limitations of using conventional drug therapies, smart cell encapsulating delivery systems have been explored to customize the treatment with alignment to disease longevity. Cell therapeutics has advanced in tandem with improvements in biomaterials that can suitably deliver therapeutic cells to achieve targeted therapy. Among the promising biomacromolecules for cell delivery are those that share bio-relevant architecture with the extracellular matrix and display extraordinary compatibility in the presence of therapeutic cells. Interestingly, many biomacromolecules that fulfil these tenets occur naturally and can form hydrogels.

AREAS COVERED

This review provides a concise incursion into the paradigm shift to cell therapeutics using biomacromolecules. Advances in the design and use of biomacromolecules to assemble smart therapeutic cell carriers is discussed in light of their pivotal role in enhancing cell encapsulation and delivery. In addition, the principles that govern the application of cell therapeutics in diabetes, neuronal disorders, cancers and cardiovascular disease are outlined.

EXPERT OPINION

Cell therapeutics promises to revolutionize the treatment of various secretory cell dysfunctions. Current and future advances in designing functional biomacromolecules will be critical to ensure that optimal delivery of therapeutic cells is achieved with desired biosafety and potency.

Gemcitabine cationic polymeric nanoparticles against ovarian cancer: formulation, characterization, and targeted drug delivery

This study focused on gemcitabine (GTB) delivery of cationic polymeric nanoparticles to treat ovarian cancer in order to promote effective localized delivery and drug retention during biological discharge. To begin, four GTB-loaded polymer nanoparticles were prepared: chitosan nanoparticles (CS-NPs), polysarcosin nanoparticles (PSar-NPs), poly-l-lysine & polysarcosin nanoparticles (PLL-PSar-NPs), and chitosan & polysarcosin nanoparticles (CS-PSar-NPs). Based on preliminary particle size, zeta potential, encapsulation efficiency, DSC, surface morphology, release profiling, and cellular internalization studies using rhodamine 123 and Nile red fluorescent markers, it was hypothesized that CS-PSar-NPs could be the best cationic formulation with strong biocompatibility and anticancer activity against the OVCAR-8 ovarian cancer cell line. To improve effective targeting, cellular penetration, and in vitro cytotoxicity, epidermal growth factor receptor variation III (EGFRvIII) is attached over all four polymeric nanoparticles. Confocal imaging revealed that EGFRvIII-conjugated cationic GTB polymeric nanoparticles had a greater cellular uptake and double internalization capabilities than unconjugated nanoparticles, as well as time-dependent cell entrance. GTB and EGFRvIII-conjugated polymer nanoparticles would have a stronger potential to infiltrate ovarian cancer cells during the first hour of incubation. According to TEM and FTIR findings, EGFRvIII conjugation across the non-target CS-PSar-NP surface was successful, making CS-PSar-NPS-EGFRvIII more target-specific and thus a safer drug delivery candidate for ovarian cancer treatment.

Highlights

GTB loaded non-target CS-PSar-NPs & active targeted CS-PSar-NPs-EGFRvII developed.

SEM, AFM, DSC, particle size, zeta potential, internalization performed for CS-PSar-NPs.

MTT & CLSM study confirmed CS-PSar-NPS-EGFRvII was binding specific to OVCAR-8 cells

Fabrication of EGFRvII over nanoparticles confirmed by TEM.

CS-PSar-NPS-EGFRvII safer candidate for ovarian cancer.

Biopolymer nanoparticles: a strategy to enhance stability, bioavailability, and biological effects of phenolic compounds as functional ingredients

Phenolic compounds are abundant in nature and have multiple beneficial effects on human health due to their antioxidant, anti-inflammatory, antithrombotic, antiallergenic, anticancer, and antiatherosclerotic properties. For this reason, phenolics are becoming relevant functional ingredients for several industries, mainly the food industry, derived from food consumer exigencies and regulations. However, the use of their beneficial properties still presents some limitations, such as chemical instability under environmental and processing conditions, which leads to structural changes and compromises their biological activities. They also present poor water solubility and sensitivity to pH changes, decreasing their bioavailability in the organism. The technologies for extraction and stabilization of these compounds have evolved rapidly in the development of different delivery systems to encapsulate sensitive active molecules. Biopolymeric nanoparticles are biodegradable polymer-based colloidal systems with sizes ranging from 1 to 1000 nm, and different techniques can be carried out to develop them. These systems have emerged as a green and effective alternative to improve stability, bioavailability, and biological effects of phenolic compounds. This comprehensive review aims to present an overview of recent advances in encapsulation processes of phenolic compounds within biopolymer nanoparticles as delivery systems and the impact on their physicochemical properties and biological effects after encapsulation. © 2021 Society of Chemical Industry.

Inorganic Fillers in Composite Gel Polymer Electrolytes for High-Performance Lithium and Non-Lithium Polymer Batteries

Among the various types of polymer electrolytes, gel polymer electrolytes have been considered as promising electrolytes for high-performance lithium and non-lithium batteries. The introduction of inorganic fillers into the polymer-salt system of gel polymer electrolytes has emerged as an effective strategy to achieve high ionic conductivity and excellent interfacial contact with the electrode. In this review, the detailed roles of inorganic fillers in composite gel polymer electrolytes are presented based on their physical and electrochemical properties in lithium and non-lithium polymer batteries. First, we summarize the historical developments of gel polymer electrolytes. Then, a list of detailed fillers applied in gel polymer electrolytes is presented. Possible mechanisms of conductivity enhancement by the addition of inorganic fillers are discussed for each inorganic filler. Subsequently, inorganic filler/polymer composite electrolytes studied for use in various battery systems, including Li-, Na-, Mg-, and Zn-ion batteries, are discussed. Finally, the future perspectives and requirements of the current composite gel polymer electrolyte technologies are highlighted.