Alginate-amphotericin B nanocomplexes covered by nanocrystals from bacterial cellulose: physico-chemical characterization and in vitro toxicity

In vitro and in vivo attenuation of Salmonella resistance using a novel synthesized chloramphenicol magnesium Nano-complex

In this study, Chloramphenicol-Mg-Nano-complex (CHL-Mg-NC) was synthesized as a novel antimicrobial agent to attenuate chloramphenicol resistant Salmonella clinical isolates in vitro and in vivo. The CHL-Mg-NC was prepared in presence of gamma radiation and validated by SEM, DLS, Zeta potential, and FTIR, that revealed typical CHL-Mg-NC characteristics. The Phenotypes, biochemical investigations and molecular identification assays defined Salmonella isolates and further detection of invA gene in S. Paratyphi A NCRR-CHR1, S. Enteritidis NCRR-CHR2 and S. Typhimurium NCRR-CHR3 were appraised. In vitro anti-Salmonella efficacy of CHL-Mg-NC was assessed against Salmonella isolates in addition to Typhimurium ATCC 700720. Gamma radiation improved CHL-Mg-NC synthesis in dose-depend manner up to 5 kGy. CHL-Mg-NC showed MIC at a range from 0.156 to 0.625 μg/mL and MBC from 0.3125 to 2.5 μg/mL with MBC/MIC ratio less than or equal to 4. CHL-Mg-NC inhibited biofilm formation in the range of 45.31 %-100 %. It also had bactericidal activity at 2MIC within the low time ranged from 2h to 4h. The in vivo efficacy of CHL-Mg-NC was observed by the reduction in the number of viable Salmonella recovered from feces in infected mice and showed evident improvement in CHL-Mg-NC treated groups.CHL-Mg-NC has no significant cytotoxic effects on normal cells and CC50 is 13.5 μg/mL against CACO2 cells. Acute toxicity of CHL-Mg-NC indicates that the CHL-Mg-NC is safe at high concentrations.

Amphotericin B Encapsulation in Polymeric Nanoparticles: Toxicity Insights via Cells and Zebrafish Embryo Testing

Background: Amphotericin B (AmB) is a commonly utilized antifungal agent, which is also recommended for the treatment of certain neglected tropical diseases, including leishmaniasis. However, its clinical application is constrained because of its poor oral bioavailability and adverse effects, prompting the investigation of alternative drug delivery systems. Polymeric nanoparticles (PNPs) have gained attention as a potential drug delivery vehicle, providing advantages such as sustained release and enhanced bioavailability, and could have potential as AmB carriers. However, concerns persist regarding nanomaterials' toxicity, requiring more studies. Zebrafish (Danio rerio) embryos were used as a valuable model for toxicity testing, especially because of their genetic similarity to humans and standardized developmental assessments. Methods: In this study, we produced and characterized AmB loaded and non-loaded PNPs by nanoprecipitation, dynamic light scattering, transmission electron microscopy, atomic force microscopy and spectroscopy. Afterwards, we verified their toxicity through in vitro MTT assays in three cell lines (HEK293, HepG2, and J774 A1) and in vivo tests with zebrafish embryos. Results: In both trials, it was noted that nanoencapsulation of the drug led to increased toxicity when compared to non-encapsulated AmB, possibly indicating that they penetrated the embryo's chorion. Nevertheless, it was demonstrated that the polymers used are safe and they are not the cause of toxicity, neither are the nanostructures per se. Conclusions: Therefore, it is believed that the objective of improving the bioavailability of AmB may have been achieved, and the observed toxicity was probably linked to AmB's ability to destabilize cell membranes.

Chemical Functionalization of Cellulose Nanofibrils with 2-Aminoethyl Hydrogen Sulfate

The chemical functionalization of cellulose nanofibrils (CNFs) was carried out using 2-aminoethyl hydrogen sulfate as the reagent under various experimental conditions via a bimolecular nucleophilic substitution (SN2) reaction. The functionalized CNFs were characterized by Fourier transform infrared spectroscopy-attenuated total reflectance. The results indicate that the chemical modification was successful, as evidenced by the presence of a band at 1540 cm-1, corresponding to the N-H bond of the amine group. Elemental analysis revealed a nitrogen content of 0.45%, and the degree of substitution was calculated to be 0.053 under the optimal reaction conditions. Atomic force microscopy analysis showed no significant changes in the morphology of the CNFs. X-ray diffraction patterns demonstrated a decrease in the crystallinity index, from 80.8% to 71.8%. Thermogravimetric analysis showed a slight reduction in thermal stability (onset temperature decreased from 229.4 to 227.5 °C) for the modified CNFs compared to the unmodified samples. Differential scanning calorimetry results indicated no significant effect of the modification on thermal behavior, with both modified and unmodified samples displaying similar thermal profiles, although the modified samples exhibited slightly higher thermal stability.

Developing multifunctional cellulose derivatives for environmental and biomedical applications: Insights into modification processes and advanced material properties

The growing bioeconomic demand for lightweight, eco-friendly materials with functional versatility and competitive mechanical properties drives the resurgence of cellulose as a sustainable scaffold for various applications. This review comprehensively scrutinizes current progressions in cellulose functional materials (CFMs), concentrating on their structure-property connections. Significant modification methods, including cross-linking, grafting, and oxidation, are discussed together with preparation techniques categorized by cellulose sources. This review article highlights the extensive usage of modified cellulose in various industries, particularly its potential in optical and toughening applications, membrane production, and intelligent bio-based systems. Prominence is located on low-cost procedures for developing biodegradable polymers and the physical-chemical characteristics essential for biomedical applications. Furthermore, the review explores the role of cellulose derivatives in smart packaging films for food quality monitoring and deep probes into cellulose's mechanical, thermal, and structural characteristics. The multifunctional features of cellulose derivatives highlight their worth in evolving environmental and biomedical engineering applications.

A Review on the Modification of Cellulose and Its Applications

The latest advancements in cellulose and its derivatives are the subject of this study. We summarize the characteristics, modifications, applications, and properties of cellulose. Here, we discuss new breakthroughs in modified cellulose that allow for enhanced control. In addition to standard approaches, improvements in different techniques employed for cellulose and its derivatives are the subject of this review. The various strategies for synthetic polymers are also discussed. The recent advancements in polymer production allow for more precise control, and make it possible to make functional celluloses with better physical qualities. For sustainability and environmental preservation, the development of cellulose green processing is the most abundant renewable substance in nature. The discovery of cellulose disintegration opens up new possibilities for sustainable techniques. Based on the review of recent scientific literature, we believe that additional chemical units of cellulose solubility should be used. This evaluation will evaluate the sustainability of biomass and processing the greenness for the long term. It appears not only crucial to dissolution, but also to the greenness of any process.

In-silico approach as a tool for selection of excipients for safer amphotericin B nanoformulations

Safer and efficacious Amphotericin B (AmB) nanoformulations can be designed by augmenting AmB in the monomeric or super-aggregated state, and restricting the aggregated state, by choosing the appropriate excipient, which can be facilitated by employing in-silico prediction as a tool. Excipients selected for the study included linear fatty acids from caprylic (C₈) to stearic(C₁₈) and the stearate based amphiphilic surfactants polyoxyl-15-hydroxystearate (PS15) and polyoxyl-40-stearate (PS40). Blend module was employed to determine the two miscibility parameters mixing energy (E_mix) and interaction parameter (χ). AmB-excipient interactions were modelled using molecular docking software. The fatty acids revealed a decrease in E_mix and χ values with increase in carbon chain length, suggesting enhanced affinity with increase in fatty acid hydrophobicity. Significantly higher affinity was observed with amphiphilic surfactants, in particular PS40 which exhibited negative values of E_mix and χ proposing very high degree of miscibility. Molecular docking study confirmed extensive interaction of all the excipients with the AmB polyene chain. PS15 and PS40 displayed in addition hydrophilic interactions with the mycosamine and polyol moieties with PS40 exhibiting complete wrapping of the AmB molecule. PS15 demonstrated only partial wrapping, attributed to the shorter ethylene oxide chain. AmB nanosuspensions (NS) were prepared by in situ nanoprecipitation using the excipients and the AmB state identified by UV scanning between 300 and 500 nm. AmB NS with fatty acids and PS15-AmB NS revealed a high intensity peak between 330 nm-350 nm of aggregated AmB and low intensity monomeric peaks between 405 and 415 nm reflecting predominance of the aggregated state. PS40-AmB NS on the other hand revealed complete absence of aggregated state and a high intensity peak between 321 and 325 nm which corresponded to the super-aggregated state. Also, the super-aggregated state slowly released the safe monomeric form without aggregate formation. Furthermore, very low hemolysis seen with PS40-AmB NS confirmed low toxicity attributed to the safer super-aggregated state and while higher hemolysis as anticipated was seen with PS15-AmB NS (aggregated state). The basis for selection of the appropriate excipient for design of safer AmB nanoformulations would be those excipients that exhibit negative values of miscibility parameters E_mix and χ, exhibit interaction with the hydrophobic and hydrophilic regions of AmB and demonstrate complete wrapping of AmB in the molecular docking study. Our study thus demonstrates feasibility of in-silico prediction as a practical tool for excipient selection for safer AmB nanoformulations.