Targeted Smart pH and Thermoresponsive N,O-Carboxymethyl Chitosan Conjugated Nanogels for Enhanced Therapeutic Efficacy of Doxorubicin in MCF-7 Breast Cancer Cells

Exploring the promising role of chitosan delivery systems in breast cancer treatment: A comprehensive review

Breast cancer presents a significant global health challenge, driving the development of novel treatment strategies for therapeutic interventions. Nanotechnology has emerged as a promising avenue for addressing this challenge, with Chitosan (CS) nanoparticles receiving prominence due to their unique characteristics and multitude of potential applications. This review provides a comprehensive overview of the role of Chitosan nanoparticles in breast cancer therapy. The review begins by emphasizing the prevalence and importance of breast cancer as a major health issue, underscoring the necessity for effective treatments. It then delves into the application of Chitosan nanoparticles in breast cancer therapy. One key aspect discussed is their role as carriers for anticancer drugs, enabling targeted delivery and improved cellular uptake. Furthermore, the review explores modified Chitosan nanoparticles and strategies for enhancing their efficacy and specificity in breast cancer treatment. It also examines Chitosan conjugates and hybrids, which offer innovative approaches for combination therapy. Additionally, metal and magnetic Chitosan nanoparticles are discussed spanning their capacity to assist in imaging, hyperthermia, as well as targeted drug delivery. In conclusion, the review summarizes the current research landscape regarding Chitosan nanoparticles for breast cancer therapy and offers insights into future directions. Overall, the review highlights the versatility, potential benefits, and future prospects of Chitosan nanoparticles in combating breast cancer.

pH-responsive chitosan-mediated spherical mesoporous silica microspheres for high loading and controlled delivery of 5-Fluorouracil

The objective of this study is to develop a drug carrier to overcome the inherent drawbacks of 5-Fluorouracil (5-Fu), including low bioavailability, short half-life, and systemic toxicity. In the present work, mesoporous silica nanoparticles (MSNs) capped by chitosan (CS) to encapsulate 5-Fu (5-Fu MSNs/CS) were fabricated by the sol-gel process, ultrasonic impregnation, and emulsion cross-linking. The 5-Fu MSNs/CS microspheres exhibit pH-responsive drug release and remarkable drug encapsulation capacity, as well as perfect sphericity, high specific surface area (680.62 cm2/g), and uniform particle size (2.64 ± 0.05 μm). The drug-loading content and encapsulation efficiency are 14.12 ± 0.53 % and 82.21 ± 2.13 %, respectively. The cumulative release of 5-Fu from MSNs/CS microspheres is fast and sustained at pH 5.0 (89.56 ± 0.97 %) compared to that at pH 7.4 (57.88 ± 0.91 %) in 96 h, and it is Fickian diffusion controlled. In conclusion, the MSNs/CS microspheres prepared in this study could be potential carriers for 5-Fu delivery.

Natural Polymer-Based Nanogel for pH-Responsive Delivery of Sorafenib Tosylate in Hemangiosarcoma

Smart nanomedicinal treatment for cancer manifests a solubility challenge with inherent nanoscale size and nonspecific release with stimuli-responsive potential. This is the limelight in novel chemotherapy to pursue physiochemical differences between the tumor microenvironment (TME) and normal cells, which introduces active groups of nanocarriers responding to various stimuli, endowing them with concise responses to various tumor-related signals. The nanogels were successfully prepared by a modified solvent evaporation technique. Nine batches were formulated by changing the chitosan concentration (12, 14, 16 mg/ml) and sonication time (5, 10, 15 min). The formulations were optimized for particle size and zeta potential with high percent entrapment efficiency (%EE) through Central Composite Design software. The optimized batch F7 had a 182-nm size and high zeta potential (64.5 mV) with 98% EE. The drug release of F7 was higher at pH 6 (97.556%) than at pH 7.4 (45.113%). The pharmacokinetic study shows that the release follows the Hixon plot model (R2 = 0.9334) that shifts to zero order (R2 = 0.9149). The nanogel F7 was observed for stability and showed an absence of color change, phase separation, and opacity for 6 months. In the present study, the pH difference between cancer cells and normal cells is the key point of the smart nanogel. This study is promising but challenging depending on the in vivo study. The nanogel was successfully prepared and evaluated for pH-responsive release. As hemangiosarcoma commonly occurs in dogs, this formulation helps to limit the difficulties with administration.

Controlled delivery of 5-fluorouracil from monodisperse chitosan microspheres prepared by emulsion crosslinking

This work aims to determine the optimal conditions for emulsion cross-linking of chitosan (CHS) with various molecular weights using glutaraldehyde as a cross-linking agent to produce 5-fluorouracil-loaded CHS microspheres (5-FU/CHS). Their drug loading and encapsulation efficiencies are found to be in the range of 3.87-12.35% and 20.13-70.45%, respectively. The dynamic light scattering results show that 5-FU/CHS microspheres are micron-sized with a uniform size distribution, and the scanning electron microscopy results show that they are spherical. The results of thermogravimetric analysis, X-ray diffraction, and Fourier transform infrared spectroscopy demonstrate that 5-FU is successfully incorporated into the microspheres. The in vitro release tests show that 5-FU/CHS have a prolonged, pH-responsive release pattern of 5-FU, and the cumulative release rate under acidic condition is much larger than that under neutral conditions. The drug release kinetic analysis further demonstrates that the release of 5-FU can be well described by the Fickian diffusion model.

Chitosan/alginate nanogel potentiate berberine uptake and enhance oxidative stress mediated apoptotic cell death in HepG2 cells

Biopolymer-based nanoscale drug delivery systems have become a promising approach to overcome the limitations associated with conventional chemotherapeutics used for cancer treatment. Herein, we reported to develop a hydrophilic nanogel (NG) composed of Chitosan (Chi) and sodium alginate (Alg) using the ion gelation method for delivering Berberine hydrochloride (BBR), an alkaloid obtained from Berberis aristata roots. The use of different nanocarriers for BBR delivery has been reported previously, but the bioavailability of these carriers was limited due to phagocytic uptake and poor systemic delivery. The developed NG showed enhanced stability and efficient entrapment of BBR ∼92 %, resulting in a significant increase in bioavailability. The pH-dependent release behavior demonstrated sustained and effective release of ∼86 %, ∼74 % and, ∼53 % BBR at pH 5.5, 6.6, and 7.4 respectively after 72h, indicating its potential as a drug carrier. Additionally, the cellular uptake of BBR was significantly higher ∼19 % in the BBR-NG (25 μM) than in bulk BBR (100 μM), leading to enhanced ROS generation, mitochondrial depolarisation, and inhibition of cell proliferation and colony formation in HepG2 cells. In summary, the results suggest that the Chi/Alg biopolymer-based nano-formulation could be an effective approach for delivering BBR and enhancing its cellular uptake, efficacy, and cytotoxicity.

Chitosan-functionalized bioplatforms and hydrogels in breast cancer: immunotherapy, phototherapy and clinical perspectives

Breast cancer is the most common and malignant tumor among women. Chitosan (CS)-based nanoparticles have been introduced into breast cancer therapy as a way to increase the targeted delivery of drugs and genes to the tumor site. CS nanostructures suppress tumorigenesis by enhancing both the targeted delivery of cargo (drug and gene) and its accumulation in tumor cells. The tumor cells internalize CS-based nanoparticles through endocytosis. Moreover, chitosan nanocarriers can also induce phototherapy-mediated tumor ablation. Smart and multifunctional types of CS nanoparticles, including pH-, light- and redox-responsive nanoparticles, can be used to improve the potential for breast cancer removal. In addition, the acceleration of immunotherapy by CS nanoparticles has also been achieved, and there is potential to develop CS-nanoparticle hydrogels that can be used to suppress tumorigenesis.

Organic Nanodelivery Systems as a New Platform in the Management of Breast Cancer: A Comprehensive Review from Preclinical to Clinical Studies

Breast cancer accounts for approximately 25% of cancer cases and 16.5% of cancer deaths in women, and the World Health Organization predicts that the number of new cases will increase by almost 70% over the next two decades, mainly due to an ageing population. Effective diagnostic and treatment strategies are, therefore, urgently required for improving cure rates among patients since current therapeutic modalities have many limitations and side effects. Nanomedicine is evolving as a promising approach for cancer management, including breast cancer, and various types of organic and inorganic nanomaterials have been investigated for their role in breast cancer diagnosis and treatment. Following an overview on breast cancer characteristics and pathogenesis and challenges of the current treatment strategies, the therapeutic potential of biocompatible organic-based nanoparticles such as liposomes and polymeric micelles that have been tested in breast cancer models are reviewed. The efficacies of different drug delivery and targeting strategies are documented, ranging from synthetic to cell-derived nanoformulations together with a summary of the interaction of nanoparticles with externally applied energy such as radiotherapy. The clinical translation of nanoformulations for breast cancer treatment is summarized including those undergoing clinical trials.

Synthesis and Evaluation of Rutin–Hydroxypropyl β-Cyclodextrin Inclusion Complexes Embedded in Xanthan Gum-Based (HPMC-g-AMPS) Hydrogels for Oral Controlled Drug Delivery

Oxidants play a significant role in causing oxidative stress in the body, which contributes to the development of diseases. Rutin—a powerful antioxidant—may be useful in the prevention and treatment of various diseases by scavenging oxidants and reducing oxidative stress. However, low solubility and oral bioavailability have restricted its use. Due to the hydrophobic nature of rutin, it cannot be easily loaded inside hydrogels. Therefore, first rutin inclusion complexes (RIC) with hydroxypropyl-β-cyclodextrin (HP-βCD) were prepared to improve its solubility, followed by incorporation into xanthan gum-based (hydroxypropyl methylcellulose-grafted-2-acrylamido -2-methyl-1-propane sulfonic acid) hydrogels for controlled drug release in order to improve the bioavailability. Rutin inclusion complexes and hydrogels were validated by FTIR, XRD, SEM, TGA, and DSC. The highest swelling ratio and drug release occurred at pH 1.2 (28% swelling ratio and 70% drug release) versus pH 7.4 (22% swelling ratio, 65% drug release) after 48 h. Hydrogels showed high porosity (94%) and biodegradation (9% in 1 week in phosphate buffer saline). Moreover, in vitro antioxidative and antibacterial studies (Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli) confirmed the antioxidative and antibacterial potential of the developed hydrogels.

Chitosan-based nanoscale systems for doxorubicin delivery: Exploring biomedical application in cancer therapy

Green chemistry has been a growing multidisciplinary field in recent years showing great promise in biomedical applications, especially for cancer therapy. Chitosan (CS) is an abundant biopolymer derived from chitin and is present in insects and fungi. This polysaccharide has favorable characteristics, including biocompatibility, biodegradability, and ease of modification by enzymes and chemicals. CS-based nanoparticles (CS-NPs) have shown potential in the treatment of cancer and other diseases, affording targeted delivery and overcoming drug resistance. The current review emphasizes on the application of CS-NPs for the delivery of a chemotherapeutic agent, doxorubicin (DOX), in cancer therapy as they promote internalization of DOX in cancer cells and prevent the activity of P-glycoprotein (P-gp) to reverse drug resistance. These nanoarchitectures can provide co-delivery of DOX with antitumor agents such as curcumin and cisplatin to induce synergistic cancer therapy. Furthermore, co-loading of DOX with siRNA, shRNA, and miRNA can suppress tumor progression and provide chemosensitivity. Various nanostructures, including lipid-, carbon-, polymeric- and metal-based nanoparticles, are modifiable with CS for DOX delivery, while functionalization of CS-NPs with ligands such as hyaluronic acid promotes selectivity toward tumor cells and prevents DOX resistance. The CS-NPs demonstrate high encapsulation efficiency and due to protonation of amine groups of CS, pH-sensitive release of DOX can occur. Furthermore, redox- and light-responsive CS-NPs have been prepared for DOX delivery in cancer treatment. Leveraging these characteristics and in view of the biocompatibility of CS-NPs, we expect to soon see significant progress towards clinical translation.

Carboxymethyl Chitosan-Modified Graphene Oxide as a Multifunctional Vector for Deltamethrin Delivery and pH-Responsive Controlled Release, Enhanced Leaf Affinity, and Improved Mosquito-Killing Activity

Traditional deltamethrin (DM) formulations (e.g., emulsifiable concentrates, wettable powders, etc.) have significant disadvantages of poor water dispersion stability, burst release, weak leaf affinity, short duration, poor efficacy, and high environmental toxicity. A nanomaterial-based pesticide delivery system (PDS) has provided effective strategies for green preparation and synergism of pesticide formulations. In this article, we developed carboxymethyl chitosan (CMCS)-modified graphene oxide (GO) as a vector for DM and constructed a pH-responsive PDS for Culex pipiens pallens control. GO-CMCS possesses excellent pesticide loading performance for DM (loading rate 87.76%). After being loading on GO-CMCS, the GO-CMCS-DM has a significantly improved dispersion stability in water. The GO-CMCS-DM exhibits pH-responsive controlled release performance, which can sustain the release of DM into the medium, maintaining an effective long-term concentration. Additionally, the leaf adhesion of GO-CMCS-DM is better than that for free DM, which can improve the pesticide utilization. Therefore, GO-CMCS-DM has a prolonged persistent period and sustained activity against Culex pipiens pallens. Considering the industrialization potential of GO, we believe that GO will play an important role in the pest control and antiepidemic fields.

Physically stimulus-responsive nanoparticles for therapy and diagnosis

Nanoparticles offer numerous advantages in various fields of science, particularly in medicine. Over recent years, the use of nanoparticles in disease diagnosis and treatments has increased dramatically by the development of stimuli-responsive nano-systems, which can respond to internal or external stimuli. In the last 10 years, many preclinical studies were performed on physically triggered nano-systems to develop and optimize stable, precise, and selective therapeutic or diagnostic agents. In this regard, the systems must meet the requirements of efficacy, toxicity, pharmacokinetics, and safety before clinical investigation. Several undesired aspects need to be addressed to successfully translate these physical stimuli-responsive nano-systems, as biomaterials, into clinical practice. These have to be commonly taken into account when developing physically triggered systems; thus, also applicable for nano-systems based on nanomaterials. This review focuses on physically triggered nano-systems (PTNSs), with diagnostic or therapeutic and theranostic applications. Several types of physically triggered nano-systems based on polymeric micelles and hydrogels, mesoporous silica, and magnets are reviewed and discussed in various aspects.

ROS-Generating Amine-Functionalized Magnetic Nanoparticles Coupled with Carboxymethyl Chitosan for pH-Responsive Release of Doxorubicin

Purpose

Methods

Results

Conclusion

Control Release of Adenosine Potentiate Osteogenic Differentiation within a Bone Integrative EGCG-g-NOCC/Collagen Composite Scaffold toward Guided Bone Regeneration in a Critical-Sized Calvarial Defect

The regeneration of critical-sized bone defects with biomimetic scaffolds remains clinically challenging due to avascular necrosis, chronic inflammation, and altered osteogenic activity. Two confounding mechanisms, efficacy manipulation, and temporal regulation dictate the scaffold's bone regenerative ability. Equally critical is the priming of the mesenchymal stromal cells (MSCs) toward lineage-specific differentiation into bone-forming osteoblast, which particularly depends on varied mechanochemical and biological cues during bone tissue regeneration. This study sought to design and develop an optimized osteogenic scaffold, adenosine/epigallocatechin gallate-N,O-carboxymethyl chitosan/collagen type I (AD/EGCG-g-NOCC@clgn I), having osteoinductive components toward swift bone regeneration in a calvarial defect BALB/c mice model. The ex vivo findings distinctly establish the pro-osteogenic potential of adenosine and EGCG, stimulating MSCs toward osteoblast differentiation with significantly increased expression of alkaline phosphatase, calcium deposits, and enhanced osteocalcin expression. Moreover, the 3D matrix recapitulates extracellular matrix (ECM) properties, provides a favorable microenvironment, structural support against mechanical stress, and acts as a reservoir for sustained release of osteoinductive molecules for cell differentiation, proliferation, and migration during matrix osteointegration observed. Evidence from in vivo experiments, micro-CT analyses, histology, and histomorphometry signify accelerated osteogenesis both qualitatively and quantitatively: effectual bone union with enhanced bone formation and new ossified tissue in 4 mm sized defects. Our results suggest that the optimized scaffold serves as an adjuvant to guide bone tissue regeneration in critical-sized calvarial defects with promising therapeutic efficacy.

Recent Biomedical Approaches for Chitosan Based Materials as Drug Delivery Nanocarriers

In recent decades, drug delivery systems (DDSs) based on nanotechnology have been attracting substantial interest in the pharmaceutical field, especially those developed based on natural polymers such as chitosan, cellulose, starch, collagen, gelatin, alginate and elastin. Nanomaterials based on chitosan (CS) or chitosan derivatives are broadly investigated as promising nanocarriers due to their biodegradability, good biocompatibility, non-toxicity, low immunogenicity, great versatility and beneficial biological effects. CS, either alone or as composites, are suitable substrates in the fabrication of different types of products like hydrogels, membranes, beads, porous foams, nanoparticles, in-situ gel, microparticles, sponges and nanofibers/scaffolds. Currently, the CS based nanocarriers are intensely studied as controlled and targeted drug release systems for different drugs (anti-inflammatory, antibiotic, anticancer etc.) as well as for proteins/peptides, growth factors, vaccines, small DNA (DNAs) and short interfering RNA (siRNA). This review targets the latest biomedical approaches for CS based nanocarriers such as nanoparticles (NPs) nanofibers (NFs), nanogels (NGs) and chitosan coated liposomes (LPs) and their potential applications for medical and pharmaceutical fields. The advantages and challenges of reviewed CS based nanocarriers for different routes of administration (oral, transmucosal, pulmonary and transdermal) with reference to classical formulations are also emphasized.

Doxorubicin-loaded composite nanogels for cancer treatment

Nanogels as a versatile vehicle for doxorubicin have attracted great attention during the last decade. Since a nanogel composite device transport encapsulated drugs to the site of action and release them in a desirable time-frame, it could provide higher therapeutic effect. By implementation of different polymers, polymer/inorganic NPs and various crosslinking chemistry, it is possible to fabricate novel composite nanogel systems with favorable characteristics such as smart intelligent systems or multipurpose platforms. Due to high stability, good drug loading capacity for hydrophobic and hydrophilic agents, nanogels introduce great opportunity in pharmaceutical innovations. Composite nanogels show capability in gene, drug and diagnostic agents' delivery while providing an ideal platform for theranostic purposes as multifunctional systems. Doxorubicin as an anticancer agent is widely used against numerous cancers. Due to high systemic toxicity of doxorubicin, there is still need for its safe and specific delivery to the site of action. In this regard, so many efforts have been put in by the researchers for preparation of different nanogel formulations of doxorubicin in order to produce more efficient formulations. This review focuses on design, fabrication, advantages and disadvantages of composite nanogel-based doxorubicin formulations.

Poly(vinyl alcohol) and Functionalized Ionic Liquid-Based Smart Hydrogels for Doxorubicin Release

Limitations associated with the traditional cancer therapies prompt the scientific community to develop effective, safer, smarter, and targeted drug carriers that improve the efficiency of the drug carrier, reduce the adverse effects of the drug on the healthy cells, and help in preventing the cancer recurrences. This research aims to design a stimuli-responsive, self-healable, adhesive, and injectable polymeric hydrogel with an ester-functionalized ionic liquid as one of the additives to improve the efficiency of the anticancer drug in encapsulation and localized delivery. The designed polymeric hydrogel responds to intracellular biological stimuli (e.g., acidic pH of cancerous cells and temperature), changes the morphology through changing the shape and size of the gelator within the hydrogel matrix, and releases encapsulated doxorubicin (DOX) at the tumor site efficiently. Molecular interactions, gel morphology, and mechanical strength of the hydrogel were characterized through various analytical techniques, including small-angle neutron scattering. Adhesive properties of the polymeric hydrogel were measured by lap-shear strength tests and the biocompatibility and cellular drug uptake study on human breast cancer (MCF-7) and human cervical carcinoma cells (HeLa). The in vitro cytotoxicity and drug release study showed that the hybrid hydrogel is more effective at killing the cancerous cells, and the targeted release of DOX occurred at intracellular acidic pH. The polymeric hydrogel provides an efficient therapeutic approach for the encapsulation and release of the drug. Overall, the study offers a proof of concept to test the feasibility of the hydrogel system whether the hydrogel formulation helped or hindered the total cellular DOX trafficking.

Stimuli-responsive Drug Delivery Nanocarriers in the Treatment of Breast Cancer

Stimuli-responsive drug-delivery nanocarriers (DDNs) have been increasingly reported in the literature as an alternative for breast cancer therapy. Stimuli-responsive DDNs are developed with materials that present a drastic change in response to intrinsic/chemical stimuli (pH, redox and enzyme) and extrinsic/physical stimuli (ultrasound, Near-infrared (NIR) light, magnetic field and electric current). In addition, they can be developed using different strategies, such as functionalization with signaling molecules, leading to several advantages, such as (a) improved pharmaceutical properties of liposoluble drugs, (b) selectivity with the tumor tissue decreasing systemic toxic effects, (c) controlled release upon different stimuli, which are all fundamental to improving the therapeutic effectiveness of breast cancer treatment. Therefore, this review summarizes the use of stimuli-responsive DDNs in the treatment of breast cancer. We have divided the discussions into intrinsic and extrinsic stimuli and have separately detailed them regarding their definitions and applications. Finally, we aim to address the ability of these stimuli-responsive DDNs to control the drug release in vitro and the influence on breast cancer therapy, evaluated in vivo in breast cancer models.

Thermoresponsive Nanogels Based on Different Polymeric Moieties for Biomedical Applications

Nanogels, or nanostructured hydrogels, are one of the most interesting materials in biomedical engineering. Nanogels are widely used in medical applications, such as in cancer therapy, targeted delivery of proteins, genes and DNAs, and scaffolds in tissue regeneration. One salient feature of nanogels is their tunable responsiveness to external stimuli. In this review, thermosensitive nanogels are discussed, with a focus on moieties in their chemical structure which are responsible for thermosensitivity. These thermosensitive moieties can be classified into four groups, namely, polymers bearing amide groups, ether groups, vinyl ether groups and hydrophilic polymers bearing hydrophobic groups. These novel thermoresponsive nanogels provide effective drug delivery systems and tissue regeneration constructs for treating patients in many clinical applications, such as targeted, sustained and controlled release.

Advancement in nanogel formulations provides controlled drug release

Nanogels are currently considered as promising nanosized drug delivery carriers. Nanogels are made of a crosslinked polymeric network which could encapsulate both hydrophilic and hydrophobic drugs due to their tunable nature. The ability of nanogels to control drug release is vastly described in the literature and researchers are consistently improving the control of drug release from nanogel by designing new polymers having specific sensitivity to a chemical or physical stimulus. In this review, we briefly discuss the definition of nanogels, their release profiles, their specific gel-based characteristics and the pathways of dug release from nanogels. We have focused on the stimuli responsive nanogels and their release profile. This compilation opens the window for understanding the influence of chemical composition and design of various nanogel on their release in the presence and absence of corresponding stimuli such as temperature, pH, enzymes and others. The uniqueness of this review is that it highlights the data of release profiles in terms of the different nanogel composition and triggers. It also points the high potential of nanogels in the list of candidates for drug delivery systems, thanks to their properties regarding drug encapsulation and release, combined advantages of nano-size and swelling characteristics of hydrogel.

Advances in controlled release pesticide formulations: Prospects to safer integrated pest management and sustainable agriculture

As the world is striving hard towards sustainable agricultural practices for a better tomorrow, one of the primary focuses is on effective pest management for enhanced crop productivity. Despite newer and potent chemicals as pesticides, there are still substantial crop losses, and if by any means this loss can be tackled; it will alleviate unwanted excessive use of chemical pesticides. Scientific surveys have already established that pesticides are not being utilized by the crops completely rather a significant amount remains unused due to various limiting factors such as leaching and bioconversion, etc., resulting in an adverse effect on human health and ecosystems. Concerted efforts from scientific diaspora toward newer and innovative strategies are already showing promise, and one such viable approach is controlled release systems (CRS) of pesticides. Moreover, to bring these smart formulations within the domain of current pesticide regulatory framework is still under debate. It is thus, paramount to discuss the pros and cons of this new technology vis-à-vis the conventional agrarian methods. This review deliberates on the developmental updates in this innovative field from the past decades and also appraises the challenges encumbered. Additionally, critical information and the foreseeable research gaps in this emerging area are highlighted.

5-Fluorouracil monodispersed chitosan microspheres: Microfluidic chip fabrication with crosslinking, characterization, drug release and anticancer activity

Different size and morphology monodispersed chitosan (CS) microspheres loaded with the anticancer drug of 5-fluorouracil (5-Fu) were prepared by the microfluidic method assisted by a crosslinking unit with crosslinkers of tripolyphosphate (TPP) and glutaraldehyde (GTA). The sizes, morphologies, drug loading, encapsulation efficiency, drug release and cytotoxicity of 5-Fu loaded CS microspheres were characterized and determined. Results indicated that the CS microspheres were uniform in size distributions. They possessed excellent encapsulation efficiency and drug loading. The TPP-crosslinked CS microspheres had rough surfaces and exhibited faster drug release, whereas the CS microspheres crosslinked with GTA had smooth surfaces and showed slower drug release. Furthermore, 5-Fu-loaded CS microspheres exhibited sustained drug release which well fitted the first-order kinetics model and were pH-responsive in that the drug cumulative release was greater at acidic environments than at neutral conditions. Finally, 5-Fu loaded CS microspheres provided sufficient cytotoxicity and were satisfactory in the cancer cell inhibition.

Polymer-Assisted In Situ Synthesis of Silver Nanoparticles with Epigallocatechin Gallate (EGCG) Impregnated Wound Patch Potentiate Controlled Inflammatory Responses for Brisk Wound Healing

Introduction

An ideal wound dressing material needs to be predisposed with desirable attributes like anti-infective effect, skin hydration balance, adequate porosity and elasticity, high mechanical strength, low wound surface adherence, and enhanced tissue regeneration capability. In this work, we have synthesized hydrogel-based wound patches having antibacterial silver nanoparticles and antioxidant epigallocatechin gallate (EGCG) and showed fast wound closure through their synergistic interaction without any inherent toxicity.

Methods and results

Wound patches were synthesized from modified guar gum polymer and assessed to determine accelerated wound healing. The modified polymer beget chemical-free in-situ synthesis of monodispersed silver NPs (~12 nm), an antimicrobial agent, besides lending ionic surface charges. EGCG impregnated during ionotropic gelation process amplified the efficacy of wound patches that possess apt tensile strength, porosity, and swellability for absorbing wound exudates. Further, in vitro studies endorsed them as non-cytotoxic and the post agent effect following exposure to the patch showed an unbiased response to E coli K12 and B. subtilis. In vivo study using sub-cutaneous wounds in Wistar rats validated its accelerated healing properties when compared to a commercially available wound dressing material (skin graft; Neuskin-F^®) through better wound contraction, promoted collagen deposition and enhanced vascularization of wound region by modulating growth factors and inflammatory cytokines.

Conclusion

Synthesized wound patches showed all the desired attributes of a clinically effective dressing material and the results were validated in various in vitro and in vivo assays.

Carboxymethyl Chitosan Modified Carbon Nanoparticle for Controlled Emamectin Benzoate Delivery: Improved Solubility, pH-Responsive Release, and Sustainable Pest Control

Environmentally friendly pesticide delivery systems have drawn extensive attention in recent years, and they show great promise in sustainable development of agriculture. We herein report a multifunctional nanoplatform, carboxymethyl chitosan modified carbon nanoparticles (CMC@CNP), as the carrier for emamectin benzoate (EB, a widely used insecticide), and investigate its sustainable antipest activity. EB was loaded on CMC@CNP nanocarrier via simple physisorption process, with a high loading ratio of 55.56%. The EB@CMC@CNP nanoformulation showed improved solubility and dispersion stability in aqueous solution, which is of vital importance to its practical application. Different from free EB, EB@CMC@CNP exhibited pH-responsive controlled release performance, leading to sustained and steady EB release and prolonged persistence time. In addition, the significantly enhanced anti-UV property of EB@CMC@CNP further ensured its antipest activity. Therefore, EB@CMC@CNP exhibited superior pest control performance than free EB. In consideration of its low cost, easy preparation, free of organic solution, and enhanced bioactivity, we expect, CMC@CNP will have a brilliant future in pest control and green agriculture.

Implementation of two different experimental designs for screening and optimization of process parameters for metformin-loaded carboxymethyl chitosan formulation

Metformin (MET) was effectively encapsulated into O-carboxymethyl chitosan (O-CMC) polymeric formulation using an experimental design method. Six factors Plackett-Burman (PB) design was utilized to find the significant process parameters. Linear equations used to study the effect of each process parameters on particle size (PS), encapsulation efficiency (EE), and zeta potential (ZP) and the most influential three factors decided for further optimization. Optimization was carried out by implementing three-factor three-level Box-Behnken (BB) design. Mathematical models were generated by regression analysis for responses of PS, EE, and ZP. Two-step experimental design took into account for the preparation of optimized formulation with maximum %EE (72.78 ± 9.7%) and minimum PS (225.67 ± 5.53 nm) at optimum process conditions with a ZP of -5.22 mV for the nano-polymeric formulation in an economical matter by reduction chemical use and formulation time. Furthermore, the biological activity of the final formulation was determined by in vitro cytotoxicity study compared to free MET. The cytotoxicity result reveals that both pure drug and nano-formulation biocompatible with MCF10A non-tumorigenic cell line and lethal for the MCF7 cell line. These in vitro results were the first helpful step to further investigate O-CMC loaded MET nanoparticles in diagnostic and therapeutic applications of breast cancer.

Chitosan for gene delivery: Methods for improvement and applications

Gene therapy is a promising strategy for treating challenging diseases. The successful delivery of genes is a critical step for gene therapy. However, concerns about immunogenicity and toxicity are the main obstacles against the widespread use of effective viral systems. Therefore, nonviral vectors are regarded as good alternatives to viral vectors. Chitosan is a natural cationic polysaccharide that could be used to create nonviral gene delivery vectors. Various methods have been developed to improve the properties of chitosan related to gene delivery. This review introduces the features of chitosan in gene delivery, summarizes current progress toward methods promoting the properties of chitosan related to gene delivery, and presents different applications of chitosan in gene delivery vectors. Finally, future prospects of gene vectors based on chitosan are discussed.

Tough robust dual responsive nanocomposite hydrogel as controlled drug delivery carrier of asprin

Smart mechanical strong hydrogels have gained increasing attention in the last decade. A novel tough robust biocompatible and dual pH- and temperature- responsive poly (N-isopropylacrylamide)/clay (Laponite XLS)/gold nanoparticles (Au-S-S NPs)/caboxymethyl chitosan (CMCTs) nanocomposite hydrogel was synthesized by a facile one-pot in situ free radical polymerization, using clay and Au-S-S NPs as the cross-linkers instead of toxic organic molecules. By tuning the crucial factors, concentration of Au-S-S NPs, CMCTs and clay, the obtained hydrogels exhibited the highest tensile stress of 535.5 kPa at the breaking deformation of 1579.5%. Furthermore, these synthesized hydrogels were tough enough and simultaneously owned a fast recoverability after unloaded in 15 min at room temperature. Moreover, effects of the above factors on swelling and swelling-shrinking behaviors of the prepared hydrogels were investigated in detail. In addition, these designed hydrogels also possessed a controlled drug release property of asprin by adjusting their inner crosslink density. Owing to this property, they could be used as the potential drug delivery carriers in future.

Important cytotoxic and cytostatic effects of new copper(i)-phosphane compounds with N,N, N,O and N,S bidentate ligands

A family of six phosphane Cu(i) complexes bearing N,N, N,O and N,S bidentate ligands was synthesized. All the compounds were fully characterized by classical analytical and spectroscopic methods, and five of them were also characterized by X-ray diffraction studies. All the compounds exhibit high cytotoxicity against the human breast cancer cell line MCF7 with IC50 values far lower than those found for cisplatin, a current chemotherapeutic in clinical use. Compounds 1[combining low line] and 3[combining low line] induce cell cycle arrest in the G2/M phase and cell death by apoptosis. The cytotoxic and cytostatic effects of these compounds on MCF7 cells suggest that they are suitable for further in vivo studies with breast cancer models.

A pH and magnetic dual-response hydrogel for synergistic chemo-magnetic hyperthermia tumor therapy

To overcome the toxicity of chemotherapy, increasing attention has been paid to local drug delivery systems (DDSs). pH-Sensitive hydrogels have emerged as promising DDS materials in the biomedical field due to their remarkable characteristics. However, the pH environment in tumor varies from person to person, which makes the applicability of systems based on pH challenging. In this study, we developed a contractible hydroxypropyl methyl cellulose (HPMC)/Fe₃O₄ hydrogel with dual-response pH and magnetic properties aiming to overcome the limitations of pH-sensitive hydrogel drug delivery systems and further increase their efficiency in tumor therapy. The HPMC/Fe₃O₄ hydrogel could act as a drug delivery system that combines pH-sensitive triggering and magnetic dual-response drug release for synergistic chemo-magnetic hyperthermia therapy. The drug delivery profile of the HPMC/Fe₃O₄/doxorubicin hydrochloride (DOX) hydrogel was determined in vitro and revealed a remarkable pH-sensitive performance. After synergistic chemo-magnetic hyperthermia treatment, mice with 4T1 breast cancer xenografts recovered without any recurrence or metastasis, demonstrating the synergistic effect of chemotherapy and magnetic hyperthermia therapy. Meanwhile, reduced toxicity and superior anticancer effects were achieved due to the combined effect of the pH and magnetic hyperthermia response properties. This study demonstrated the high efficacy and low toxicity of the improved design of HPMC/Fe₃O₄ for drug delivery, which may provide a promising approach for the application of chemo-magnetic hyperthermia cancer therapy.

A pH and magnetic dual-responsive hydrogel highly sensitive to tumor acid microenvironment and efficient responsive magnetic-hyperthermia cancer eradication.

Inhibition of Thioredoxin Reductase by Targeted Selenopolymeric Nanocarriers Synergizes the Therapeutic Efficacy of Doxorubicin in MCF7 Human Breast Cancer Cells

Increasing evidence suggests selenium nanoparticles (Se NPs) as potential cancer therapeutic agents and emerging drug delivery carriers, yet, the molecular mechanism of their anticancer activity still remains unclear. Recent studies indicate thioredoxin reductase (TrxR), a selenoenzyme, as a promising target for anticancer therapy. The present study explored the TrxR inhibition efficacy of Se NPs as a plausible factor impeding tumor growth. Hyaluronic acid (HA)-functionalized selenopolymeric nanocarriers (Se@CMHA NPs) were designed wielding chemotherapeutic potential for target specific Doxorubicin (DOX) delivery. Se@CMHA nanocarriers are thoroughly characterized asserting their chemical and physical integrity and possess prolonged stability. DOX-loaded selenopolymeric nanocarriers (Se@CMHA-DOX NPs) exhibited enhanced cytotoxic potential toward human cancer cells compared to free DOX in an equivalent concentration eliciting its selectivity. In first-of-its-kind findings, selenium as Se NPs in these polymeric carriers progressively inhibit TrxR activity, further augmenting the anticancer efficacy of DOX through a synergistic interplay between DOX and Se NPs. Detailed molecular studies on MCF7 cells also established that upon exposure to Se@CMHA-DOX NPs, MCF7 cells endure G2/M cell cycle arrest and p53-mediated caspase-independent apoptosis. To gauge the relevance of the developed nanosystem in in vivo settings, three-dimensional tumor sphere model mimicking the overall tumor environment was also performed, and the results clearly depict the effectiveness of our nanocarriers in reducing tumor activity. These findings are reminiscent of the fact that our Se@CMHA-DOX NPs could be a viable modality for effective cancer chemotherapy.

Recent advances in engineered chitosan-based nanogels for biomedical applications

Recent progress in the preparation and biomedical applications of engineered chitosan-based nanogels has been comprehensively reviewed.