Novel nanoparticles composed of chitosan and β-cyclodextrin derivatives as potential insoluble drug carrier

Graphene/carbohydrate polymer composites as emerging hybrid materials in tumor therapy and diagnosis

Despite the introduction of various types of treatments for cancer control, cancer therapy faces several challenges such as aggressive behavior, heterogeneous characteristics, and the development of resistance. In contrast, the methods have depended on the creation and formulation of nanoparticles to impede tumor growth. Carbon nanoparticles have attracted considerable attention for cancer therapy, with graphene nanoparticles emerging as promising vehicles for delivering drugs and genes. Moreover, graphene composites can enhance immunotherapy, phototherapy, and combination therapies. Nonetheless, the biocompatibility and toxicity of graphene composites present difficulties. Consequently, this manuscript assesses the alteration of graphene nanocomposites using carbohydrate polymers. Altering graphene composites with carbohydrate polymers such as chitosan, hyaluronic acid, cellulose, and starch can enhance their efficacy in cancer treatment. Furthermore, graphene composites functionalized with carbohydrate polymers for tumor ablation induced by phototherapy. Graphene oxide and graphene quantum dots have been modified with carbohydrate polymers to enhance their therapeutic and diagnostic uses. These nanoparticles can transport gene therapy techniques like siRNA in the treatment of cancer. Despite the breakdown of these nanoparticles within the body, they maintain excellent biosafety and biocompatibility.

Amelioration of Cancer Employing Chitosan, Its Derivatives, and Chitosan-Based Nanoparticles: Recent Updates

The limitations associated with the conventional treatment of cancer have necessitated the design and development of novel drug delivery systems based mainly on nanotechnology. These novel drug delivery systems include various kinds of nanoparticles, such as polymeric nanoparticles, solid lipid nanoparticles, nanostructured lipid carriers, hydrogels, and polymeric micelles. Among the various kinds of novel drug delivery systems, chitosan-based nanoparticles have attracted the attention of researchers to treat cancer. Chitosan is a polycationic polymer generated from chitin with various characteristics such as biocompatibility, biodegradability, non-toxicity, and mucoadhesiveness, making it an ideal polymer to fabricate drug delivery systems. However, chitosan is poorly soluble in water and soluble in acidic aqueous solutions. Furthermore, owing to the presence of reactive amino groups, chitosan can be chemically modified to improve its physiochemical properties. Chitosan and its modified derivatives can be employed to fabricate nanoparticles, which are used most frequently in the pharmaceutical sector due to their possession of various characteristics such as nanosize, appropriate pharmacokinetic and pharmacodynamic properties, non-immunogenicity, improved stability, and improved drug loading capacity. Furthermore, it is capable of delivering nucleic acids, chemotherapeutic medicines, and bioactives using modified chitosan. Chitosan and its modified derivative-based nanoparticles can be targeted to specific cancer sites via active and passive mechanisms. Based on chitosan drug delivery systems, many anticancer drugs now have better effectiveness, potency, cytotoxicity, or biocompatibility. The characteristics of chitosan and its chemically tailored derivatives, as well as their use in cancer therapy, will be examined in this review.

Stimuli-responsive cyclodextrin-based supramolecular assemblies as drug carriers

Cyclodextrins (CDs) are widely employed in biomedical applications because of their unique structures. Various biomedical applications can be achieved in a spatiotemporally controlled manner by integrating the host-guest chemistry of CDs with stimuli-responsive functions. In this review, we summarize the recent advances in stimuli-responsive supramolecular assemblies based on the host-guest chemistry of CDs. The stimuli considered in this review include endogenous (pH, redox, and enzymes) and exogenous stimuli (light, temperature, and magnetic field). We mainly discuss the mechanisms of the stimuli-responsive ability and present typical designs of the corresponding supramolecular assemblies for drug delivery and other potential biomedical applications. The limitations and perspectives of CD-based stimuli-responsive supramolecular assemblies are discussed to further promote the translation of laboratory products into clinical applications.

Enhanced Oral Bioavailability of Epalrestat SBE7-β-CD Complex Loaded Chitosan Nanoparticles: Preparation, Characterization and in-vivo Pharmacokinetic Evaluation

Background

Epalrestat (EPL) is a carboxylic acid derivative with poor aqueous solubility and its pharmacokinetic features are not fully defined.

Purpose

Current research aimed to fabricate inclusion complexation of EPL with SBE₇ β-CD (IC) and EPL/SBE₇ β-CD CS NPs (NP).

Methods

EPL was complexed with SBE₇ β-CD using the co-precipitation method, and the prepared complex was fabricated into nanoparticles using the ionic gelation method. The prepared formulations were characterized for particle size analysis, surface morphology, and in vitro dissolution study. The % inhibition of EPL against α-glucosidase enzyme was also conducted to check the drug’s antidiabetic activity. Finally, an in vivo pharmacokinetic investigation was carried out to determine the concentration of EPL in rabbit plasma of the prepared formulation. In vivo pharmacokinetic studies were conducted by giving a single dose of pure EPL, IC, and NP.

Results

The size of NP was found to be 241.5 nm with PDI 0.363 and zeta potential of +31.8 mV. The surface of the prepared NP was non-porous, smooth and spherical when compared with pure EPL, SBE₇ β-CD and IC. The cumulative drug release (%) from IC and NP was 73% and 88%, respectively, as compared to pure drug (25%). The % inhibition results for in vitro α-glucosidase was reported to be 74.1% and the predicted binding energy for in silico molecular docking was calculated to be −6.6 kcal/mol. The calculated C_max values for EPL, IC and NP were 4.75±3.64, 66.91±7.58 and 84.27±6.91 μg/mL, respectively. The elimination half-life of EPL was 4 h and reduced to 2 h for IC and NP. The AUC_0-α for EPL, IC and NP were 191.5±164.63, 1054.23±161.77 and 1072.5±159.54 μg/mL*h, respectively.

Conclusion

Taking these parameters into consideration it can be concluded that IC and NP have prospective applications for greatly improved delivery and regulatedt release of poorly water soluble drugs, potentially leading to increase therapeutic efficacy and fewer side effects.

Utilization of Gelling Polymer to Formulate Nanoparticles Loaded with Epalrestat-Cyclodextrin Inclusion Complex: Formulation, Characterization, In-Silico Modelling and In-Vivo Toxicity Evaluation

Epalrestat (EPL) is an aldose reductase inhibitor with poor aqueous solubility that affects its therapeutic efficacy. The research study was designed to prepare epalrestat-cyclodextrins (EPL-CDs) inclusion complexes to enhance the aqueous solubility by using beta-cyclodextrin (β-CD) and sulfobutyl ether₇ β-CD (SBE₇ β-CD). Furthermore, polymeric nanoparticles (PNPs) of EPL-CDs were developed using chitosan (CS) and sodium tripolyphosphate (sTPP). The EPL-CDs complexed formulations were then loaded into chitosan nanoparticles (CS NPs) and further characterized for different physico-chemical properties, thermal stability, drug-excipient compatibility and acute oral toxicity studies. In-silico molecular docking of cross-linker with SBE₇ β-CD was also carried out to determine the binding site of the CDs with the cross-linker. The sizes of the prepared NPs were laid in the range of 241.5–348.4 nm, with polydispersity index (PDI) ranging from 0.302–0.578. The surface morphology of the NPs was found to be non-porous, smooth, and spherical. The cumulative percentage of drug release from EPL-CDs loaded CS NPs was found to be higher (75–88%) than that of the pure drug (25%). Acute oral toxicity on animal models showed a biochemical, histological profile with no harmful impact at the cellular level. It is concluded that epalrestat-cyclodextrin chitosan nanoparticles (EPL-CDs-CS NPs) with improved solubility are safe for oral administration since no toxicity was reported on vital organs in rabbits.

Solid Polymeric Nanoparticles of Albendazole: Synthesis, Physico-Chemical Characterization and Biological Activity

Albendazole is a benzimidazole derivative with documented antitumor activity and low toxicity to healthy cells. The major disadvantage in terms of clinical use is its low aqueous solubility which limits its bioavailability. Albendazole was incorporated into stable and homogeneous polyurethane structures with the aim of obtaining an improved drug delivery system model. Spectral and thermal analysis was used to investigate the encapsulation process and confirmed the presence of albendazole inside the nanoparticles. The in vitro anticancer properties of albendazole encapsulated in polyurethane structures versus the un-encapsulated compound were tested on two breast cancer cell lines, MCF-7 and MDA-MB-231, in terms of cellular viability and apoptosis induction. The study showed that the encapsulation process enhanced the antitumor activity of albendazole on the MCF-7 and MDA-MB-23 breast cancer lines. The cytotoxic activity manifested in a concentration-dependent manner and was accompanied by changes in cell morphology and nuclear fragmentation.

Mesalazine/hydroxypropyl-β-cyclodextrin/chitosan nanoparticles with sustained release and enhanced anti-inflammation activity

This study aimed to develop a novel sustained release system for mesalazine (MSZ) by preparing hydroxypropyl-β-cyclodextrin (HP-β-CD) inclusion complex loaded chitosan (CS) nanoparticles (NPs). The HP-β-CD/MSZ complex was prepared at 1:1 stoichiometry and characterized by using various analysis techniques. The HP-β-CD/MSZ/CS NPs prepared under the optimum condition had a spherical shape (90±17 nm diameter), a narrow size distribution, and a high loading efficiency. Compared with free MSZ, the HP-β-CD/MSZ/CS NPs exhibited an obvious sustained release of MSZ. The activity of the NPs against a cytokine-triggered inflammatory response was evaluated in cytokine-stimulated HT-29 cell lines by monitoring key inflammatory mediators. The results revealed that compared with free MSZ, the NPs more strongly inhibited the production of NO, PGE₂, and IL-8, indicating the NPs possibly had better anti-inflammatory effects. Therefore, the established HP-β-CD/MSZ/CS NPs may be a promising delivery system of MSZ.

Preparation and characterization of β-cyclodextrin grafted N-maleoyl chitosan nanoparticles for drug delivery

β-cyclodextrin (CD) grafted N-maleoyl chitosan (CD-g-NMCS) with two different degrees of substitution (DS) of N-maleoyl (DS = 21.2% and 30.5%) were synthesized from maleic anhydride and chitosan bearing pendant cyclodextrin (CD-g-CS). CD-g-NMCS based nanoparticles were prepared via an ionic gelation method together with chitosan and CD-g-CS nanoparticles. The size and zeta potential of prepared CD-g-NMCS nanoparticles were 179.2~274.0 nm and 36.2~42.4 mV, respectively. In vitro stability test indicated that CD-g-NMCS nanoparticles were more stable in phosphate-buffered saline compared with chitosan nanoparticles. Moreover, a poorly water-soluble drug, ketoprofen (KTP), was selected as a model drug to study the obtained nanoparticle's potentials as drug delivery carriers. The drug loading efficiency of CD-g-NMCS20 nanoparticles were 14.8% for KTP. MTT assay showed that KTP loaded CD-g-NMCS nanoparticles were safe drug carriers. Notably, in vitro drug release studies showed that KTP was released in a sustained-release manner for the nanoparticles. The pharmacokinetic of drug loaded CD-g-NMCS20 nanoparticles were evaluated in rats after intravenous administration. The results of studies revealed that, compared with free KTP, KTP loaded CD-g-NMCS20 nanoparticles exhibited a significant increase in AUC0→24h and mean residence time by 6.6-fold and 2.9-fold, respectively. Therefore, CD-g-NMCS nanoparticles could be used as a novel promising nanoparticle-based drug delivery system for sustained release of poorly water-soluble drugs. The carboxylic acid groups of the CD-g-NMCS molecule provide convenient sites for further structural modifications including introduction of tissue- or disease- specific targeting groups.

Size-dependent penetration of nanoemulsions into epidermis and hair follicles: implications for transdermal delivery and immunization

Nanoemulsions have been widely applied to dermal and transdermal drug delivery. However, whether and to what depth the integral nanoemulsions can permeate into the skin is not fully understood. In this study, an environment-responsive dye, P4, was loaded into nanoemulsions to track the transdermal translocation of the nanocarriers, while coumarin-6 was embedded to represent the cargoes. Particle size has great effects on the transdermal transportation of nanoemulsions. Integral nanoemulsions with particle size of 80 nm can diffuse into but not penetrate the viable epidermis. Instead, these nanoemulsions can efficiently fill the whole hair follicle canals and reach as deep as 588 μm underneath the dermal surfaces. The cargos are released from the nanoemulsions and diffuse into the surrounding dermal tissues. On the contrary, big nanoemulsions, with mean particle size of 500 nm, cannot penetrate the stratum corneum and can only migrate along the hair follicle canals. Nanoemulsions with median size, e.g. 200 nm, show moderate transdermal permeation effects among the three-size nanoemulsions. In addition, colocalization between nanoemulsions and immunofluorescence labeled antigen-presenting cells was observed in the epidermis and the hair follicles, implying possible capture of nanoemulsions by these cells. In conclusion, nanoemulsions are advantageous for transdermal delivery and potential in transcutaneous immunization.

β-Cyclodextrin-Based Inclusion Complexation Bridged Biodegradable Self-Assembly Macromolecular Micelle for the Delivery of Paclitaxel

In this study, a novel adamantanamine-paclitaxel (AD-PTX) incorporated oligochitosan- carboxymethyl-β-cyclodextrin (CSO-g-CM-β-CD) self-assembly macromolecular (CSO-g-CM-β-CD@AD-PTX) micelle was successfully prepared in water through sonication. The formed molecules were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance (NMR) spectroscopy, two-dimensional NMR, elemental analysis, and liquid chromatography-mass spectrometry, while the correspondent micelles were characterized by dynamic light scattering and transmission electron microscopy. We showed that the macromolecular micelle contained a spherical core-shell structure with a diameter of 197.1 ± 3.3 nm and zeta potential of -19.1 ± 4.3 mV. The CSO-g-CM-β-CD@AD-PTX micelle exhibited a high drug-loading efficacy up to 31.3%, as well as a critical micelle concentration of 3.4 × 10-7 M, which indicated good stability. Additionally, the in vitro release profile of the CSO-g-CM-β-CD@AD-PTX micelle demonstrated a long-term release pattern, 63.1% of AD-PTX was released from the micelle during a 30-day period. Moreover, the CSO-g-CM-β-CD@AD-PTX micelle displayed cytotoxicity at a sub-μM scale similar to PTX in U87 MG cells, and CSO-g-CM-β-CD exhibited a good safety profile by not manifesting significant toxicity at concentrations up to 100 μM. These results indicated that β-CD-based inclusion complexation resulting in biodegradable self-assembled macromolecular micelles can be utilized as nanocarrier, and may provide a promising platform for drug delivery in the future medical applications.