Lactobionic acid-modified thymine-chitosan nanoparticles as potential carriers for methotrexate delivery

5-Fluorouracil-loaded green chitosan nanoparticles/ guar gum nanocomposite hydrogel in controlled drug delivery

In recent years nanotechnologies have been applied to human health with promising results, especially in the field of drug delivery. Polymeric nanoparticles (NPs) have garnered much importance in controlled drug delivery owing to their size. Chitosan (Cs) is a well-recognized biopolymer and Cs NPs have been widely explored in drug delivery. Nonetheless, reports pertaining to green synthesis of Cs NPs are scarce. Thus, in this study, green synthesis of Cs NPs was accomplished from raw mango peel extract. Spherical Cs NPs with positively charged surface of 33.4 mV was accomplished by this process. Cs NPs, in varied content, were integrated in a guar gum network matrix resulting in a nanocomposite hydrogel. The mechanical and thermal stability of the hydrogel improved upon addition of Cs NPs. The hydrogel exhibited smart swelling, good antioxidant and anti-inflammatory propensities. Cs NPs encapsulating 5-Fluorouracil demonstrated a controlled release drug profile in the colorectum and the kinetics implied the anomalous nature of drug release mechanism. The exposure of the drug-loaded nanocomposite hydrogel displayed improved anticancer effects in HT-29 colon cancer cells. Taken altogether, this study puts forth the greater efficacy of Cs NPs in controlled drug delivery for anticancer therapy.

An update review of smart nanotherapeutics and liver cancer: opportunities and challenges

Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer, typically diagnosed in advanced stages. Chemotherapy is necessary for treating advanced liver cancer; however, several challenges affect its effectiveness. These challenges include low specificity, high dosage requirements, high systemic toxicity and severe side effects, which significantly limit the efficacy of chemotherapy. These limitations can hinder the treatment of HCC. This review focuses on the prevalence of HCC, different types of liver cancer and the staging of the disease, along with available treatment methods. Additionally, explores recent and relevant studies on smart drug- and gene-delivery systems specifically designed for HCC. These systems include targeted endogenous and exogenous stimuli-responsive platforms.

Reactive oxygen species-responsive thymine-conjugated chitosan: Synthesis and evaluation as cryogel

Chitosan (CS) is a biodegradable, biocompatible cationic polysaccharide based natural polymer with antibacterial and anti-inflammatory properties. Hydrogels made from CS have been found their applications in wound healing, tissue regeneration and drug delivery. Although, mucoadhesive properties resulted from the polycationic nature of CS, in hydrogel form amines are engaged in interactions with water leading to decrease in mucoadhesive properties. In case of injury, presence of elevated level of reactive oxygen species (ROS) has inspired many drug delivery platform to conjugate ROS responsive linkers for on demand drug delivery. In this report we have conjugated a reactive oxygen species (ROS) responsive thioketal (TK) linker and nucleobase thymine (Thy) with CS. Cryogel from this doubly functionalized polymer CS-Thy-TK was prepared through crosslinking with sodium alginate. Inosine was loaded on the scaffold and studied for its release under oxidative condition. We anticipated that the presence of thymine shall retain the mucoadhesive nature of the CS-Thy-TK polymer in hydrogel form and when placed at the site of injury, due to the presence of excessive ROS at inflammatory condition, loaded drug shall release due to degradation of the linker. Porous cryogel scaffold was prepared via chemical crosslinking of amine functional group of chitosan with carboxylic acid containing polysaccharide sodium alginate. The cryogel was evaluated for porosity (FE-SEM), rheology, swelling, degradation, mucoadhesive properties and biocompatibility. Resulted scaffold was found to be porous with average pore size of 107 ± 23 μm, biocompatible, hemocompatible and possesses improved mucoadhesive property (mucin binding efficiency of 19.54 %) which was found to be 4 times better as compared to chitosan (4.53 %). The cumulative drug release found to be better in the presence of H₂O₂ (~90 %) when compared to that of PBS alone (~60-70 %)_. Therefore, the modified CS-Thy-TK polymer may hold potential as interesting scaffold in case of conditions associated with elevated ROS level such as injury and tumor.

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.

pH Responsive Abelmoschus esculentus Mucilage and Administration of Methotrexate: In-Vitro Antitumor and In-Vivo Toxicity Evaluation

The rapid progression in biomaterial nanotechnology apprehends the potential of non-toxic and potent polysaccharide delivery modules to overcome oral chemotherapeutic challenges. The present study is aimed to design, fabricate and characterize polysaccharide nanoparticles for methotrexate (MTX) delivery. The nanoparticles (NPs) were prepared by Abelmoschus esculentus mucilage (AEM) and chitosan (CS) by the modified coacervation method, followed by ultra-sonification. The NPs showed much better pharmaceutical properties with a spherical shape and smooth surface of 213.4–254.2 nm with PDI ranging between 0.279–0.485 size with entrapment efficiency varying from 42.08 ± 1.2 to 72.23 ± 2.0. The results revealed NPs to possess positive zeta potential and a low polydispersity index (PDI). The in-vitro drug release showed a sustained release of the drug up to 32 h with pH-dependence. Blank AEM -CS NPs showed no in-vivo toxicity for a time duration of 14 days, accompanied by high cytotoxic effects of optimized MTX loaded NPs against MCF-7 and MD-MBA231 cells by MTT assay. In conclusion, the findings advocated the therapeutic potential of AEM/CS NPs as an efficacious tool, offering a new perspective for pH-responsive routing of anticancer drugs with tumor cells as a target.

Surface-enhanced Raman spectroscopy and density functional theory study of thymine-1-acetic acid interaction with silver nanoparticles

Thymine-1-acetic acid (TAA) is a modified nucleobase often used to add thymine functionality to materials. This study reports the Raman band assignments for TAA by comparing its experimental and density functional theory (DFT) simulated Raman spectra. Further comparison of experimental surface-enhanced Raman spectroscopy (SERS) of TAA on silver nanoparticles (Ag NPs) with simulated spectra of various complexes of xAg+ (x = 1, 2, or 3) and TAA reveals its likely adsorption orientation on the Ag NPs. This is one of the few studies that has achieved reasonably accurate simulation of SERS by employing multiple unconnected Ag+ ions, which could represent a compromise between a single atom or ion on one hand and a computationally expensive cluster on the other.

Chitosan as an Underrated Polymer in Modern Tissue Engineering

Chitosan is one of the most well-known and characterized materials applied in tissue engineering. Due to its unique chemical, biological and physical properties chitosan is frequently used as the main component in a variety of biomaterials such as membranes, scaffolds, drug carriers, hydrogels and, lastly, as a component of bio-ink dedicated to medical applications. Chitosan's chemical structure and presence of active chemical groups allow for modification for tailoring material to meet specific requirements according to intended use such as adequate endurance, mechanical properties or biodegradability time. Chitosan can be blended with natural (gelatin, hyaluronic acid, collagen, silk, alginate, agarose, starch, cellulose, carbon nanotubes, natural rubber latex, κ-carrageenan) and synthetic (PVA, PEO, PVP, PNIPPAm PCL, PLA, PLLA, PAA) polymers as well as with other promising materials such as aloe vera, silica, MMt and many more. Chitosan has several derivates: carboxymethylated, acylated, quaternary ammonium, thiolated, and grafted chitosan. Its versatility and comprehensiveness are confirming by further chitosan utilization as a leading constituent of innovative bio-inks applied for tissue engineering. This review examines all the aspects described above, as well as is focusing on a novel application of chitosan and its modifications, including the 3D bioprinting technique which shows great potential among other techniques applied to biomaterials fabrication.