Hybrid PEGylated chitosan/PLGA nanoparticles designed as pH-responsive vehicles to promote intracellular drug delivery and cancer chemotherapy

Advances in the delivery of anticancer drugs by nanoparticles and chitosan-based nanoparticles

Cancer is the leading cause of death globally, and conventional treatments have limited efficacy with severe side effects. The use of nanotechnology has the potential to reduce the side effects of drugs by creating efficient and controlled anticancer drug delivery systems. Nanoparticles (NPs) used as drug carriers offer several advantages, including enhanced drug protection, biodistribution, selectivity and, pharmacokinetics. Therefore, this review is devoted to various organic (lipid, polymeric) as well as inorganic nanoparticles based on different building units and providing a wide range of potent anticancer drug delivery systems. Within these nanoparticulate systems, chitosan (CS)-based NPs are discussed with particular emphasis due to the unique properties of CS and its derivatives including non-toxicity, biodegradability, mucoadhesivity, and tunable physico-chemical as well as biological properties allowing their alteration to specifically target cancer cells. In the context of streamlining the nanoparticulate drug delivery systems (DDS), innovative nanoplatform-based cancer therapy pathways involving passive and active targeting as well as stimuli-responsive DDS enhancing overall orthogonality of developed NP-DDS towards the target are included. The most up-to-date information on delivering anti-cancer drugs using modern dosage forms based on various nanoparticulate systems and, specifically, CSNPs, are summarised and evaluated concerning their benefits, limitations, and advanced applications.

Functional exosomes modified with chitosan effectively alleviate anthracycline-induced cardiotoxicity

Anthracyclines belong to a class of anti-tumor antibiotics, and their severe cardiotoxicity significantly limits their clinical use. Exosomes play key roles in intercellular communication, characterized by high biocompatibility and specific tissue and organ homing effects. In this study, doxorubicin, an anthracycline anticancer drug widely used in clinical chemotherapy, was selected as a model drug. To address the significant cardiotoxicity associated with doxorubicin, tumor exosomes are utilized as drug carriers. The homing effect of autologous exosomes enhances drug uptake by tumor cells and reduces cardiotoxicity. To enhance the stability of exosomes, improve therapeutic effectiveness, and reduce toxic side effects, chitosan was utilized to modify the surface of exosomes. Chitosan has a specific anti-tumor effect because it can target the CD44 receptor of tumor stem cells and interact with tumor cells through charge adsorption. Through in vitro cell experiments, in vivo pharmacokinetic experiments, and an in situ ectopic nude mouse tumor model, the study demonstrated that chitosan-modified tumor exosomes significantly alleviated the severe cardiotoxicity of doxorubicin, while also showing remarkable anti-tumor efficacy. This study introduces a novel approach to reduce the adverse side effects of anthracycline chemotherapeutic drugs and presents a highly promising nanocarrier delivery system.

A "Dual-Key-and-Lock" MRI Contrast Agent with T1-T2 Switchable Function for Accurate Diagnosis of Tumors

Extremely small iron oxide nanoparticle (ESIONP)-based stimuli-responsive switchable MRI contrast agents (CAs) show great promise for accurate detection of tumors due to their outstanding advantages of high specificity and low background signal. However, currently developed ESIONP-based switchable CAs often suffer single-biomarker-induced responses, which lack absolute specificity to pathological tissues, potentially diminishing diagnostic accuracy. In this study, weak acidity and hypoxia, two of the most remarkable characteristics of tumors, are introduced as dual biomarker stimuli to construct an ESIONP-based switchable MRI CA (DKL-CA), with its signal switch controlled by a "dual-key-and-lock" strategy. Only when DKL-CA is exposed to a coexisting weakly acidic and hypoxic environment can monodispersed ESIONPs form nanoclusters, thereby realizing a switch from the T1 to T2 contrast. Moreover, DKL-CA exhibits favorable biosafety and the capacity for precise tumor diagnosis in tumor-bearing mice. Overall, DKL-CA paves the way for designing highly accurate ESIONP-based MRI CAs for tumor diagnosis.

Unveiling the potential of chitosan-coated lipid nanoparticles in drug delivery for management of critical illness: a review

Chitosan (CT), a natural, cationic, chemically stable molecule, biocompatible, biodegradable, nontoxic, polysaccharide derived from the deacetylation of chitin, has very uniquely surfaced as a material of promise for drug delivery and biomedical applications. For the oral, ocular, cutaneous, pulmonary, and nose-to-brain routes, CT-coated nanoparticles (CTCNPs) have numerous advantages, consisting of improved controlled drug release, physicochemical stability, improved cell and tissue interactions, and increased bioavailability and efficacy of the active ingredient. CTCNPs have a broad range of therapeutic properties including anticancer, antiviral, antifungal, anti-inflammatory, antibacterial properties, treating neurological disorders, and other diseases. This has led to substantial research into the many potential uses of CT as a drug delivery vehicle. CT has also been employed in a wide range of biomedical processes, including bone and cartilage tissue regeneration, ocular tissue regeneration, periodontal tissue regeneration, heart tissue regeneration, and wound healing. Additionally, CT has been used in cosmeceutical, bioimaging, immunization, and gene transfer applications. CT exhibits a number of biological activities, which are the basis for its remarkable potential for use as a drug delivery vehicle, and these activities are covered in detail in this article. The alterations applied to CT to obtain the necessary properties have been described.

Unveiling Interactions of Tumor-Targeting Nanoparticles with Lipid Bilayers Using a Titratable Martini Model

pH-responsive nanoparticles are ideal vehicles for drug delivery and are widely used in cell imaging in targeted therapy of cancer, which usually has a weakly acidic microenvironment. In this work, we constructed a titratable molecular model for nanoparticles grafted with ligands of pH-sensitive carboxylic acids and investigated the interactions between the nanoparticles and the lipid bilayer in varying pH environments. We mainly examined the effect of the grafting density of the pH-sensitive ligands of the nanoparticles on the interactions of the nanoparticles with the lipid bilayer. The results show that the nanoparticles can penetrate the lipid bilayer only when the pH value is lower than a critical value, which can be readily modulated to the specific pH value of the tumor microenvironment by changing the ligand grafting density. This work provides some insights into modulating the interactions between the pH-sensitive nanoparticles and cellular membranes to realize targeted drug delivery to tumors based on their specific pH environment.

Pioneering Astaxanthin-Tumor Cell Membrane Nanoparticles for Innovative Targeted Drug Delivery on Melanoma

Background

Recently, the use of the tumor or its secretions as drug carriers has gradually become popular, with the advantages of high biocompatibility and enhanced drug delivery to specific cells. Melanoma is the most malignant tumor of all skin cancers; it is the most metastatic and, therefore, the most difficult to treat. The main purpose of this study is to develop nanovesicles with tumor cell membrane secretion properties to encapsulate target substances to enhance the therapeutic effect of cancer.

Methods

Astaxanthin was selected as an anticancer drug due to our previous research finding that astaxanthin has extremely high antioxidant, anti-ultraviolet damage, and anti-tumor properties. The manufacturing method of the astaxanthin nanovesicle carrier is to mix melanoma cells and astaxanthin in an appropriate ratio and then remove the genetic material and inflammatory factors of cancer cells by extrusion.

Results

In terms of results, after the co-culture of astaxanthin nanovesicles and melanoma cancer cells, it was confirmed that the ability of astaxanthin nanovesicles to inhibit the growth and metastasis of melanoma cancer cells was significantly better than the same amount of astaxanthin alone, and it had no effect on normal Human cells are also effective. There was no apparent harm on normal cells, indicating the ability of the vesicles to be selectively transported.

Conclusion

Our findings illustrated the potential of astaxanthin nanovesicles as an anticancer drug.

Nanotherapeutics for prostate cancer treatment: A comprehensive review

Prostate cancer (PCa) is the most prevalent solid organ malignancy and seriously affects male health. The adverse effects of prostate cancer therapeutics can cause secondary damage to patients. Nanotherapeutics, which have special targeting abilities and controlled therapeutic release profiles, may serve as alternative agents for PCa treatment. At present, many nanotherapeutics have been developed to treat PCa and have shown better treatment effects in animals than traditional therapeutics. Although PCa nanotherapeutics are highly attractive, few successful cases have been reported in clinical practice. To help researchers design valuable nanotherapeutics for PCa treatment and avoid useless efforts, herein, we first reviewed the strategies and challenges involved in prostate cancer treatment. Subsequently, we presented a comprehensive review of nanotherapeutics for PCa treatment, including their targeting methods, controlled release strategies, therapeutic approaches and mechanisms. Finally, we proposed the future prospects of nanotherapeutics for PCa treatment.

Exploring the potential of pH-sensitive polymers in targeted drug delivery

The pH-sensitive polymers have attained significant attention in the arena of targeted drug delivery (TDD) because of their exceptional capability to respond to alteration in pH in various physiological environments. This attribute aids pH-sensitive polymers to act as smart carriers for therapeutic agents, transporting them precisely to target locations while curtailing the release of drugs in off-targeted sites, thereby diminishing side effects. Many pH-responsive polymers in TDD have revealed promising results, with increased therapeutic efficacy and decreased toxic effects. Several pH-sensitive polymers, including, hydroxy-propyl-methyl cellulose, poly (methacrylic acid) (Eudragit series), poly (acrylic acid), and chitosan, have been broadly studied for their myriad applications in the management of various types of diseases. Additionally, the amalgamation of pH-sensitive polymers with, additive manufacturing techniques like 3D printing, has resulted in the progression of novel drug delivery systems that regulate drug release in a controlled manner. Herein, types of pH-sensitive polymers in TDD are systemically reviewed. We have briefly discussed the nanocarriers employed for the delivery of various pH-sensitive polymers in TDD. Finally, miscellaneous applications of pH-sensitive polymers are discussed thoroughly with special attention to the implication of 3D printing in pH-sensitive polymers.

Optimized DOX Drug Deliveries via Chitosan-Mediated Nanoparticles and Stimuli Responses in Cancer Chemotherapy: A Review

Chitosan nanoparticles (NPs) serve as useful multidrug delivery carriers in cancer chemotherapy. Chitosan has considerable potential in drug delivery systems (DDSs) for targeting tumor cells. Doxorubicin (DOX) has limited application due to its resistance and lack of specificity. Chitosan NPs have been used for DOX delivery because of their biocompatibility, biodegradability, drug encapsulation efficiency, and target specificity. In this review, various types of chitosan derivatives are discussed in DDSs to enhance the effectiveness of cancer treatments. Modified chitosan-DOX NP drug deliveries with other compounds also increase the penetration and efficiency of DOX against tumor cells. We also highlight the endogenous stimuli (pH, redox, enzyme) and exogenous stimuli (light, magnetic, ultrasound), and their positive effect on DOX drug delivery via chitosan NPs. Our study sheds light on the importance of chitosan NPs for DOX drug delivery in cancer treatment and may inspire the development of more effective approaches for cancer chemotherapy.

Photothermal nanozymes to self-augment combination cancer therapy by dual-glutathione depletion and hyperthermia/acidity-activated hydroxyl radical generation

Chemodynamic therapy (CDT) has emerged as a promising strategy for tumor treatment. Nevertheless, the low Fenton catalytic efficiency and the high concentration of glutathione (GSH) in cancer cells largely decline antitumor efficacy of CDT. To self-augment antitumor effect of the CDT by combining with photothermal therapy (PTT), the unique photothermal nanozymes that doubly depleted GSH, and generated massive hydroxyl radicals (·OH) in the hyperthermia/acidity-activated manner were developed. Through the coordination of Fe3+ ions with PEGylated chitosan (PEG-CS)-modified polydopamine (PDA) nanoparticles, the attained Fe3+@PEG-CS/PDA nanozymes showed outstanding colloidal stability, photothermal conversion efficiency and acidity-triggered Fe3+ release. By GSH-mediated valence states transition of Fe3+ ions and Michael reaction between GSH and quinone-rich PDA, the nanozymes sufficiently executed dual depletion of GSH with the elevated temperature.Under mimic tumor acidity and near-infrared (NIR) irradiation condition, the endocytosed nanozymes effectively converted intracellular H2O2 into toxic ·OH upon amplified Fenton reaction, thereby potently killing 4T1 cancer cells and RAW 264.7 cells. Importantly, the nanozymes prominently suppressed 4T1 tumor growth in vivo and metastasis of cancer cells by CDT/PTT combination therapy without significant systemic toxicity. Our study provides novel visions in design of therapeutic nanozymes with great clinical translational prospect for tumor treatment.

PEGylated Chitosan Nanoparticles Loaded with Betaine and Nedaplatin Hamper Breast Cancer: In Vitro and In Vivo Studies

The current study investigates the anticancer effects of PEGylated chitosan nanoparticles (CS NPs) coloaded with betaine (BT) and nedaplatin (ND) on breast adenocarcinoma (MCF-7) cells and breast cancer-bearing rats. Hereof, the ionotropic gelation approach was implemented for the synthesis of PEG-uncoated and PEG-coated CS NPs encompassing either BT, ND, or both (BT-ND). The sizes of the developed BT/CS NPs, ND/CS NPs, and BT-ND/CS NPs were 176.84 ± 7.45, 204.1 ± 13.6, and 201.1 ± 23.35 nm, respectively. Meanwhile, the sizes of the synthesized BT/PEG-CS NPs, ND/PEG-CS NPs, and BT-ND/PEG-CS NPs were 165.1 ± 32.40, 148.2 ± 20.98, and 143.7 ± 7.72 nm, respectively. The surface charges of the fabricated nanoparticles were considerably high. All of the synthesized nanoparticles displayed a spherical form and significant entrapment efficiency. Release experiments demonstrated that the PEGylated and non-PEGylated CS NPs could discharge their contents into the tumor cells' microenvironments (pH 5.5). In addition, the NPs demonstrated an outstanding ability to reduce the viability of the MCF-7 cell line. In addition, BT-ND/PEG-CS NPs were found to be the strongest among all NP preparations, where they caused around 90% decrease in the size of mammary gland tumors in rats compared to vehicle-treated animals.

Advances in preparation, biomedical, and pharmaceutical applications of chitosan-based gold, silver, and magnetic nanoparticles: A review

During the last decades, the ever-increasing incidence of various diseases, like cancer, has led to a high rate of death worldwide. On the other hand, conventional modalities (such as chemotherapy and radiotherapy) have not indicated enough efficiency in the diagnosis and treatment of diseases. Thus, potential novel approaches should be taken into consideration to pave the way for the suppression of diseases. Among novel approaches, biomaterials, like chitosan nanoparticles (CS NPs, N-acetyl-glucosamine and D-glucosamine), have been approved by the FDA for some efficient pharmaceutical applications. These NPs owing to their physicochemical properties, modification with different molecules, biocompatibility, serum stability, less immune response, suitable pharmacokinetics and pharmacodynamics, etc. have received deep attention among researchers and clinicians. More importantly, the impact of CS polysaccharide in the synthesis, preparation, and delivery of metallic NPs (like gold, silver, and magnetic NPs), and combination of CS with these metallic NPs can further facilitate the diagnosis and treatment of diseases. Metallic NPs possess some features, like converting NIR photon energy into thermal energy and anti-microorganism capability, and can be a potential candidate for the diagnosis and treatment of diseases in combination with CS NPs. These combined NPs would be efficient pharmaceuticals in the future.

Polymer Vesicles with Integrated Photothermal Responsiveness

Functionalized polymer vesicles have been proven to be highly promising in biomedical applications due to their good biocompatibility, easy processability, and multifunctional responsive capacities. However, photothermal-responsive polymer vesicles triggered by near-infrared (NIR) light have not been widely reported until now. Herein, we propose a new strategy for designing NIR light-mediated photothermal polymer vesicles. A small molecule (PTA) with NIR-triggered photothermal features was synthesized by combining a D-D'-A-D'-D configuration framework with a molecular rotor function (TPE). The feasibility of the design strategy was demonstrated through density functional theory calculations. PTA moieties were introduced in the hydrophobic segment of a poly(ethylene glycol)-poly(trimethylene carbonate) block copolymer, of which the carbonate monomers were modified in the side chain with an active ester group. The amphiphilic block copolymers (PEG44-PTA2) were then used as building blocks for the self-assembly of photothermal-responsive polymer vesicles. The new class of functionalized polymer vesicles inherited the NIR-mediated high photothermal performance of the photothermal agent (PTA). After NIR laser irradiation for 10 min, the temperature of the PTA-Ps aqueous solution was raised to 56 °C. The photothermal properties and bilayer structure of PTA-Ps after laser irradiation were still intact, which demonstrated that they could be applied as a robust platform in photothermal therapy. Besides their photothermal performance, the loading capacity of PTA-Ps was investigated as well. Hydrophobic cargo (Cy7) and hydrophilic cargo (Sulfo-Cy5) were successfully encapsulated in the PTA-Ps. These properties make this new class of functionalized polymer vesicles an interesting platform for synergistic therapy in anticancer treatment.

Biomedical applications of PLGA nanoparticles in nanomedicine: advances in drug delivery systems and cancer therapy

INTRODUCTION

During the last decades, the ever-increasing proportion of patients with cancer has been led to serious concerns worldwide. Therefore, the development and use of novel pharmaceuticals, like nanoparticles (NPs)-based drug delivery systems (DDSs), can be potentially effective in cancer therapy.

AREA COVERED

Poly lactic-co-glycolic acid (PLGA) NPs, as a kind of bioavailable, biocompatible, and biodegradable polymers, have approved by the Food and Drug Administration (FDA) for some biomedical and pharmaceutical applications. PLGA is comprised of lactic acid (LA) and glycolic acid (GA) and their ratio could be controlled during various syntheses and preparation approaches. LA/GA ratio determines the stability and degradation time of PLGA; lower content of GA results in fast degradation. There are several approaches for preparing PLGA NPs that can affect their various aspects, such as size, solubility, stability, drug loading, pharmacokinetics, and pharmacodynamics, and so on.

EXPERT OPINION

These NPs have indicated the controlled and sustained drug release in the cancer site and can use in passive and active (via surface modification) DDSs. This review aims to provide an overview of PLGA NPs, their preparation approach and physicochemical aspects, drug release mechanism and the cellular fate, DDSs for efficient cancer therapy, and status in the pharmaceutical industry and nanomedicine.

Smart chitosan-PLGA nanocarriers functionalized with surface folic acid ligands against lung cancer cells

Lung cancer is the second most prevalent and first killer cancer worldwide, and conventional approaches do not have enough ability to suppress it. Therefore, a novel targeted chitosan (CS)-poly lactic-co-glycolic acid (PLGA)-folic acid (FA) nanocarrier was developed for delivery of sorafenib (Sor) to lung cancer cells. The nanocarrier (CPSF) had a size of 30-40 nm with globular shapes. Surface charge and drug content of CPSF were ascertained at about 1.1 mV and 15 %, respectively. Controlled (4 % within 2 h) and pH-sensitive (18 % within 2 h at pH = 5.0) Sor release were observed for the nanocarrier. The MTT assay demonstrated a cell viability of 13 % after 24 h treatment with 400 nM CPSF in A549 cancer cells while it was 78 % in MSC normal cells. The qRT-PCR revealed >8 folds and 11 folds increase for Caspase9 and P53 genes after 5 h treatment with 100 nM (IC₅₀) CPSF; but a reduction of 5 folds was observed for the Bcl2 gene. Besides, 57 % and 20 % apoptosis were attained in cell cycle arrest and apoptosis assays for CPSF, respectively. CPF indicated about 88 % internalization in cancer cells. These data prove that CPSF is a promising nanodelivery system for lung cancer suppression.

Multifunctional Nanoplatform-Mediated Chemo-Photothermal Therapy Combines Immunogenic Cell Death with Checkpoint Blockade to Combat Triple-Negative Breast Cancer and Distant Metastasis

Background

Breast cancer has become the most common cancer in women. Compare with other subtypes of breast cancer, triple-negative breast cancer (TNBC) is more likely to relapse and metastasize. Highly effective therapeutic strategies are desperately needed to be explored. In this study, a multifunctional nanoplatform is expected to mediate chemo-photothermal therapy, which can combine immunogenic cell death with checkpoint blockade to combat TNBC and distant metastasis.

Methods

Poly (lactic acid-glycolic acid)-Poly (ethylene glycol) (PLGA-PEG) nanoparticles (NPs), a type of polymeric NPs, loaded with IR780, a near-infrared (NIR) dye, and doxorubicin (DOX) as the chemotherapeutic drug, were assembled by an improved double emulsification method (designated as IDNPs). The characterization, intracellular uptake, biosafety, photoacoustic (PA) imaging performance, and biodistribution of IDNPs were studied. Chemo-photothermal therapeutic effect and immunogenic cell death (ICD) were evaluated both in vitro and in vivo. The potency of chemo-photothermal therapy-triggered ICD in combination with anti-PD-1 immune checkpoint blockade (ICB) immunotherapy in eliciting immune response and treating distant tumors was further investigated.

Results

IR780 and DOX were successfully loaded into PLGA-PEG to form the IDNPs, with size of 243.87nm and Zeta potential of -6.25mV. The encapsulation efficiency of IR780 and DOX was 83.44% and 5.98%, respectively. IDNPs demonstrated remarkable on-site accumulation and PA imaging capability toward 4T1 TNBC models. Chemo-photothermal therapy demonstrated satisfactory therapeutic effects both in vitro and in vivo, and triggered ICD efficiently. ICD, in combination with anti-PD-1, provoked a systemic antitumor immune response against distant tumors.

Conclusion

Multifunctional IDNPs were successfully synthesized to mediate chemo-photothermal therapy, which combines immunogenic cell death with checkpoint blockade to combat TNBC and distant metastasis, showing great promise preclinically and clinically.

Polymeric Micellar Systems-A Special Emphasis on "Smart" Drug Delivery

Concurrent developments in anticancer nanotechnological treatments have been observed as the burden of cancer increases every year. The 21st century has seen a transformation in the study of medicine thanks to the advancement in the field of material science and nanomedicine. Improved drug delivery systems with proven efficacy and fewer side effects have been made possible. Nanoformulations with varied functions are being created using lipids, polymers, and inorganic and peptide-based nanomedicines. Therefore, thorough knowledge of these intelligent nanomedicines is crucial for developing very promising drug delivery systems. Polymeric micelles are often simple to make and have high solubilization characteristics; as a result, they seem to be a promising alternative to other nanosystems. Even though recent studies have provided an overview of polymeric micelles, here we included a discussion on the "intelligent" drug delivery from these systems. We also summarized the state-of-the-art and the most recent developments of polymeric micellar systems with respect to cancer treatments. Additionally, we gave significant attention to the clinical translation potential of polymeric micellar systems in the treatment of various cancers.

Chitosan-Based Nanoparticles as Effective Drug Delivery Systems-A review

Chitosan-based nanoparticles (chitosan-based nanocomposites; chitosan nanoparticles; ChNPs) are promising materials that are receiving a lot of attention in the last decades. ChNPs have great potential as nanocarriers. They are able to encapsulate drugs as well as active compounds and deliver them to a specific place in the body providing a controlled release. In the article, an overview has been made of the most frequently used preparation methods, and the developed applications in medicine. The presentation of the most important information concerning ChNPs, especially chitosan's properties in drug delivery systems (DDS), as well as the method of NPs production was quoted. Additionally, the specification and classification of the NPs' morphological features determined their application together with the methods of attaching drugs to NPs. The latest scientific reports of the DDS using ChNPs administered orally, through the eye, on the skin and transdermally were taken into account.

Clay nanosheets simultaneously intercalated and stabilized by PEGylated chitosan as drug delivery vehicles for cancer chemotherapy

Montmorillonite (MMT) has been frequently utilized as drug vehicles due to its high specific surface area, excellent cation exchange capacity and biocompatibility. However, the significant flocculation of MMT under physiological condition restricted its application to drug delivery. To conquer this problem, the graft-type PEGylated chitosan (PEG-CS) adducts were synthesized as intercalator to stabilize MMT dispersion. Through electrostatic attraction between the chitosan and MMT, the PEG-CS adducts were adsorbed on MMT surfaces and intercalated into MMT. The resulting PEG-CS/MMT nanosheets possessed PEG-rich surfaces, thus showing outstanding dispersion in serum-containing environment. Moreover, the physicochemical characterization revealed that the increased mass ratio of PEG-CS to MMT led to the microstructure transition of PEG-CS/MMT nanosheets from multilayered to exfoliated structure. Interestingly, the PEG-CS/MMT nanosheets with mass ratio of 8.0 in freeze-dried state exhibited a hierarchical lamellar structure organized by the intercalated MMT bundles and unintercalated PEG-CS domains. Notably, the multilayered PEG-CS/MMT nanosheets showed the capability of loading doxorubicin (DOX) superior to the exfoliated counterparts. Importantly, the DOX@PEG-CS/MMT nanosheets endocytosed by TRAMP-C1 cells liberated the drug progressively within acidic organelles, thereby eliciting cell apoptosis. This work provides a new strategy of achieving the controllable dispersion stability of MMT nanoclays towards application potentials in drug delivery.

Chitosan-Based Nanoparticles with Optimized Parameters for Targeted Delivery of a Specific Anticancer Drug-A Comprehensive Review

Chitosan is a positively charged polysaccharide obtained through chitin deacetylation. It belongs to a group of biodegradable, bioavailable, and non-toxic materials of natural origin; thus, it is a promising matrix for creating delivery systems of different active agents. Recently, much attention has been paid to nanodelivery systems as carriers to enable better bioavailability, and thus higher efficiency of the loaded drug. The present review is focused on the progress in chitosan-based nanoparticles for the targeted delivery of antitumor drugs. The paper discusses literature reports from the last three years in which chitosan nanoparticles were applied as carriers for active substances used in antitumor therapy and potential new drugs with anticancer properties. Special attention was paid to the different treatments applied to increase the therapeutic effectiveness and minimize the side effects of a specific active substance.

Onion-like doxorubicin-carrying polymeric nanomicelles with tumor acidity-sensitive dePEGylation to expose positively-charged chitosan shell for enhanced cancer chemotherapy

To effectively promote antitumor potency of doxorubicin (DOX), a regularly used chemotherapy drug, the tumor acidity-responsive polymeric nanomicelles from self-assembly of the as-synthesized amphiphilic benzoic imine-containing PEGylated chitosan-g-poly(lactic-co-glycolic acid) (PLGA) conjugates were developed as vehicles of DOX. The attained PEGylated chitosan-g-PLGA nanomicelles with high PEGylation degree (H-PEG-CSPNs) were characterized to exhibit a "onion-like" core-shell-corona structure consisting of a hydrophobic PLGA core covered by benzoic imine-rich chitosan shell and outer hydrophilic PEG corona. The DOX-carrying H-PEG-CSPNs (DOX@H-PEG-CSPNs) displayed robust colloidal stability under large-volume dilution condition and in a serum-containing aqueous solution of physiological salt concentration. Importantly, the DOX@H-PEG-CSPNs in weak acidic milieu undergoing the hydrolysis of benzoic imine bonds and increased protonation of chitosan shell showed dePEGylation and surface charge conversion. Also, the considerable swelling of protonated chitosan shell within DOX@H-PEG-CSPNs accelerated drug release. Notably, the cellular internalization of DOX@H-PEG-CSPNs by TRAMP-C1 prostate cancer cells under mimic acidic tumor microenvironment was efficiently boosted upon acidity-triggered detachment of PEG corona and exposure of positively-charged chitosan shell, thus augmenting DOX-mediated anticancer effect. Compared to free DOX molecules, the DOX@H-PEG-CSPNs appreciably suppressed TRAMP-C1 tumor growth in vivo, thereby showing great promise in improving DOX chemotherapy.