Preparation, characterization, drug release and computational modelling studies of antibiotics loaded amorphous chitin nanoparticles

Influence of degree of substitution on the hydroxypropyl-β-cyclodextrin complexation with rifampicin in water solution: a molecular simulation

CONTEXT

Hydroxypropyl-β-cyclodextrin (HPβCD) is one of the derivatized cyclodextrins most widely used as an excipient in the pharmaceutical industry, for its capacity to improve certain drugs properties. Different configurations of HPβCD are possible depending on the number and location of the 2-hydroxypropyl groups substituted on the glucose rings. Rifampicin has become the most commonly clinically used antibiotic against tuberculosis in recent years, despite its low solubility and variable bioavailability. Different techniques and materials have been proposed to enhance the properties of rifampicin: cyclodextrin complexation is one of them. The van der Waals term was the main contribution to the interaction energy, which then decisively conditioned the complex configurations. The size of rifampicin did not allow the whole molecule to fit into the host. Moreover, interaction energy was much greater when the guest was located near each rim of HPβCD, where rifampicin was partially included in the cavity and formed inclusion complexes. The piperazine tail of rifampicin was included inside the host in minimum energy structures and the guest was situated near the primary rim of HPβCD in most cases, although the complex configurations depended on the degree of substitution.

METHODS

A molecular mechanics simulation based on the GROMOS 53A6 force field was applied in this work to study the inclusion complexes formed by twelve configurations of HPβCD, with different degrees of substitution and rifampicin in water solution. We determined the penetration potential, the complex structures with minimum energies, the possibility of forming inclusion complexes other than those of minimum energies and potential energy surfaces.

Polysaccharides for Medical Technology: Properties and Applications

Over the past decade, the use of polysaccharides has gained tremendous attention in the field of medical technology. They have been applied in various sectors such as tissue engineering, drug delivery system, face mask, and bio-sensing. This review article provides an overview and background of polysaccharides for biomedical uses. Different types of polysaccharides, for example, cellulose and its derivatives, chitin and chitosan, hyaluronic acid, alginate, and pectin are presented. They are fabricated in various forms such as hydrogels, nanoparticles, membranes, and as porous mediums. Successful development and improvement of polysaccharide-based materials will effectively help users to enhance their quality of personal health, decrease cost, and eventually increase the quality of life with respect to sustainability.

Natural polysaccharide-based biodegradable polymeric platforms for transdermal drug delivery system: a critical analysis

Natural biodegradable polymers generally include polysaccharides (starch, alginate, chitin/chitosan, hyaluronic acid derivatives, etc.) and proteins (collagen, gelatin, fibrin, etc.). In transdermal drug delivery systems (TDDS), these polymers play a vital role in controlling the device's drug release. It is possible that natural polymers can be used for TDDS to attain predetermined drug delivery rates due to their physicochemical properties. These polymers can be employed to market products and scale production because they are readily available and inexpensive. As a result of these polymers, new pharmaceutical delivery systems can be developed that is both regulated and targeted. The focus of this article is the application of a biodegradable polymeric platform based on natural polymers for TDDS. Due to their biocompatibility and biodegradability, natural biodegradable polymers are frequently used in biomedical applications. Additionally, these natural biodegradable polymers are being studied for their characteristics and behaviors.

Biomolecular engineering of drugs loading in Riboflavin-targeted polymeric devices: simulation and experimental

The synthesis of polymeric nanoparticles (NPs) with efficient drug loading content and targeting moieties is an attractive field and remains a challenge in drug delivery systems. Atomistic investigations can provide an in-depth understanding of delivery devices and reduce the number of expensive experiments. In this paper, we studied the self-assembly of poly (lactic-co-glycolic acid)-b-poly (ethylene glycol) with different molecular weights and surface compositions. The innovation of this molecular study is the loading of an antitumor drug (docetaxel) on a targeting ligand (riboflavin). According to this work, a novel, biocompatible and targeted system for cancer treatment has been developed. The obtained results revealed a correlation between polymer molecular weight and the stability of particles. In this line, samples including 20 and 10 w/w% moiety NPs formed from polymers with 3 and 4.5 kDa backbone sizes, respectively, are the stable models with the highest drug loading and entrapment efficiencies. Next, we evaluated NP morphology and found that NPs have a core/shell structure consisting of a hydrophobic core with a shell of poly (ethylene glycol) and riboflavin. Interestingly, morphology assessments confirmed that the targeting moiety located on the surface can improve drug delivery to receptors and cancerous cells. The developed models provided significant insight into the structure and morphology of NPs before the synthesis and further analysis of NPs in biological environments. However, in the best cases of this system, Dynamic Light Scattering (DLS) tests were also taken and the results were consistent with the results obtained from All Atom and Coarse Grained simulations.

Evolution of the Computational Pharmaceutics Approaches in the Modeling and Prediction of Drug Payload in Lipid and Polymeric Nanocarriers

This review describes different trials to model and predict drug payload in lipid and polymeric nanocarriers. It traces the evolution of the field from the earliest attempts when numerous solubility and Flory-Huggins models were applied, to the emergence of molecular dynamic simulations and docking studies, until the exciting practically successful era of artificial intelligence and machine learning. Going through matching and poorly matching studies with the wet lab-dry lab results, many key aspects were reviewed and addressed in the form of sequential examples that highlighted both cases.

Supramolecular self-assembled drug delivery system (SADDs) of vancomycin and tocopherol succinate as an antibacterial agent: in vitro, in silico and in vivo evaluations

In this study self-assembled drug delivery system (SADDs) composed of a hydrophobic d-α-tocopherol succinate (TS) and a hydrophilic vancomycin (VCM) were formulated, and its potential for enhancing the antibacterial activity of VCM against Staphylococcus aureus (SA) and Methicillin-resistant Staphylococcus aureus (MRSA) were explored. The SADDs were synthesized via supramolecular complexation, then characterized for in silico, in vitro and in vivo studies. In silico studies confirmed the self-assembly of VCM/TS into NPs. The size, surface charge and drug loading of the SADDs was ˂100 nm, -27 mV and 68%, respectively. The SADDs were non-hemolytic and biosafe. A sustained release of VCM from SADDs was noted, with 52.2% release after 48 hr. The in vitro antibacterial test showed a twofold decrease in Minimum inhibitory concentration (MIC) against SA and MRSA, and a significantly higher reduction in MRSA biofilms compared to bare VCM. Further, in silico studies confirmed strong and stable binding of TS to MRSA efflux pumps. The in vivo study using mice skin infection models showed a 9.5-fold reduction in bacterial load after treatment with SADDs, in comparison with bare VCM. These findings affirmed that VCM/TS NPs as a promising novel nano-delivery for treating bacterial infections.

Supramolecular hydrogel containing multi-generation poly(L-lysine) dendrons for sustained co-delivery of docetaxel and matrix metallopeptidase-9 short hairpin RNA plasmid

To obtain an efficient drug and gene co-delivery hydrogel, methoxy polyethylene glycol was reacted with the caprolactone units to form the MPEG-PCL block copolymer through the polymerization reaction, which is amphiphilic and can load the hydrophobic drugs. Then, MPEG-PCL conjugated with a multi-generation poly(L-lysine) dendron to form the guest molecule MPEG-PCL-PLLD. After interacted with α-cyclodextrin through host–guest inclusion, the drug and gene dual carrier of supramolecular hydrogel was obtained. The physical properties of the hydrogel, such as the gelation time, the hydrogel strength, or its shear viscosity, could be modulated by the hose molecule of α-cyclodextrin content. MPEG-PCL-PLLD could co-load the drug and gene effectively. After gelation, the loaded drug and gene could be released sustainedly, and the release rate of them was also modulated by the α-cyclodextrin content. The supramolecular hydrogel showed a sustained effect on tumor cells and could induce the cell apoptosis sustainedly. Moreover, the co-delivery strategy was superior to only drug or gene used in tumor cell inhibition. This supramolecular hydrogel as the high-efficiency and sustained co-delivery system showed a promising application in a long-term tumor therapy.

Recent Advances in Biomaterials Science and Engineering Research in India: A Minireview

Biomedical research in health innovation and product development encompasses convergent technologies that primarily integrate biomaterials science and engineering at its core. Particularly, research in this area is instrumental for the implementation of biomedical devices (BMDs) that offer innovative solutions to help maintain and improve quality of life of patients worldwide. Despite achieving extraordinary success, implantable BMDs are still confronted with complex engineering and biological challenges that need to addressed for augmenting device performance and prolonging lifetime in vivo. Biofabrication of tissue constructs, designing novel biomaterials and employing rational biomaterial design approaches, surface engineering of implants, point of care diagnostics and micro/nano-based biosensors, smart drug delivery systems, and noninvasive imaging methodologies are among strategies exploited for improving clinical performance of implantable BMDs. In India, advances in biomedical technologies have dramatically advanced health care over the last few decades and the country is well-positioned to identify opportunities and translate emerging solutions. In this article, we attempt to capture the recent advances in biomedical research and development progressing across the country and highlight the significant research work accomplished in the areas of biomaterials science and engineering.

Applications of cellulose and chitin/chitosan derivatives and composites as antibacterial materials: current state and perspectives

The bacterial infections have always a serious problem to public health. Scientists are developing new antibacterial materials to overcome this problem. Polysaccharides are promising biopolymers due to their diverse biological functions, low toxicity, and high biodegradability. Chitin and chitosan have antibacterial properties due to their cationic nature, while cellulose/bacterial cellulose does not possess any antibacterial activity. Moreover, the insolubility of chitin in common solvents, the poor solubility of chitosan in water, and the low mechanical properties of chitosan have restricted their biomedical applications. In order to solve these problems, chemical modifications such as quaternization, carboxymethylation, cationization, or surface modification of these polymers with different antimicrobial agents, including metal and metal oxide nanoparticles, are carried out to obtain new materials with improved physiochemical and biological properties. This mini review describes the recent progress in such derivatives and composites with potential antibacterial applications.