Lignin nanoparticles (LNPs) were prepared with the objective of evaluating their application as a novel oral drug delivery system. Curcumin, a polyphenolic natural compound, was used as a lipophilic drug model, as its poor solubility and low oral bioavailability limit its therapeutic efficacy. Optimized nanoparticles were prepared using phase separation and stabilized by citric acid crosslinking. Physicochemical properties of the prepared curcumin-loaded nanoparticles, including particle size, size distribution, morphology, and encapsulation efficiency were characterized. The average particle diameter of curcumin-loaded LNPs was 104 nm, whereas the encapsulation efficiency of curcumin in the nanoparticles was 92%. Stability analyses of curcumin-loaded nanoparticles demonstrated enhanced protection of the entrapped curcumin under storage conditions. Furthermore, in vitro release assays revealed that curcumin-loaded LNPs have high stability in simulated gastric fluid and slow release under intestinal conditions as desirable. To evaluate absorption and bioavailability, we also investigated cellular uptake and transepithelial permeability of curcumin-loaded LNPs using Caco-2 cell monolayers. Cell viability studies revealed that curcumin-loaded LNPs did not induce toxicity in Caco-2 cells. The nanoparticle formulation enhanced curcumin cellular uptake and intestinal permeation compared to free curcumin. Incubation of LNPs on a Caco-2 cell monolayer led to a fivefold increase in apparent permeability compared to free curcumin. Furthermore, in vivo pharmacokinetics experiments showed that the LNP system increased the bioavailability of curcumin by ten-fold compared with the administration of unformulated curcumin. Overall, our findings indicate that the novel LNPs have great potential to be applied as an effective oral drug delivery system, especially for drug molecules with low solubility and limited bioavailability.

Due to their inexpensive and eco-friendly nature, and existence of manganese in various oxidation states and their natural abundance have attained significant attention for the formation of Mn3O4 nanoparticles (Mn3O4 NPs). Herein, we report the preparation of Mn3O4 nanoparticles using manganese nitrate as a precursor material by utilization of a precipitation technique. The as-prepared Mn3O4 nanoparticles (Mn3O4 NPs) were characterized by using X-ray powder diffraction (XRD), UV–Visible spectroscopy (UV–Vis), High-Resolution Transmission electron microscopy (HRTEM), Field emission scanning electron microscopy (FESEM), Thermal gravimetric analysis (TGA) and Fourier-transform infrared spectroscopy (FT-IR). The antimicrobial properties of the as-synthesized Mn3O4 nanoparticles were investigated against numerous bacterial and fungal strains including S. aureus, E. coli, B. subtilis, P. aeruginosa, A. flavus and C. albicans. The Mn3O4 NPs inhibited the growth of S. aureus with a minimum inhibitory concentration (MIC) of 40 μg/ml and C. albicans with a MIC of 15 μg/ml. Furthermore, the Mn3O4 NPs anti-cancer activity was examined using MTT essay against A549 lung and MCF-7 breast cancer cell lines. The Mn3O4 NPs revealed significant activity against the examined cancer cell lines A549 and MCF-7. The IC50 values of Mn3O4 NPs with A549 cell line was found at concentration of 98 µg/mL and MCF-7 cell line was found at concentration of 25 µg/mL.

Nanotechnology and nanoparticles (NPs) have increasingly been studied as an alternative for antibiotics because of the feasibility to be used in implantable devices both for bacterial detection and infection prevention. The low rate of resistance development against NPs because of its multiple mode of action has contributed to its increased acceptance in clinical setting. Further development of NPs and their anticancer activity against many human cancer cell lines including breast and ovarian have been documented. Fe₂O₃-NPs could be used for antibacterial and anticancer activity assessment. Iron oxide, apart from being available extensively and cheap, also plays a role in multiple biological processes, making it an interesting metal for NPs. The aim of the present study revolves around generation and characterization of iron oxide Fe₂O₃-NPs, followed by assessment of its antimicrobial and anticancer activities. Synthesis of Fe₂O₃-NPs was performed by hydrothermal approach, and its characterization was done by UV-visible, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) analyses, and transmission electron microscopy (TEM). Antimicrobial activity was checked by agar diffusion assay against Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, and Candida albicans. Anticancer activity of the NPs was assessed using the human cancer cell lines including cervical carcinoma cell line (HeLa) and MCF7. The developed Fe₂O₃-NPs exhibited a characteristic absorption curve in the 500-600nm wavelength range by UV-visible analysis, the XRD peaks were found to index the rhombohedral shape, and the FTIR analysis ascertained the bonds and functional groups at wavenumber from 400 to 4000cm^-1. Antimicrobial assay detected significant effect against Staphylococcus aureus and Bacillus subtilis with zones of inhibition: 21 and 22mm, respectively. Likewise, Fe₂O₃-NPs show good activity towards tested fungal strain Candida albicans with zone of inhibition of 24mm. The 2,5-diphenyl-2H-tetrazolium bromide (MTT) assay identified significant anticancer activity of the NPs against both cell lines. Our study documents the successful generation and characterization of Fe₂O₃-NPs having excellent antimicrobial and anticancer activities.

Bacterial strains resistant to antimicrobial treatments, such as antibiotics, have emerged as serious clinical problems, necessitating the development of novel bactericidal materials. Nanostructures with particle sizes ranging from 1 to 100 nanometers have appeared recently as novel antibacterial agents, which are also known as “nanoantibiotics”. Nanomaterials have been shown to exert greater antibacterial effects on Gram-positive and Gram-negative bacteria across several studies. Antibacterial nanofilms for medical implants and restorative matters to prevent bacterial harm and antibacterial vaccinations to control bacterial infections are examples of nanoparticle applications in the biomedical sectors. The development of unique nanostructures, such as nanocrystals and nanostructured materials, is an exciting step in alternative efforts to manage microorganisms because these materials provide disrupted antibacterial effects, including better biocompatibility, as opposed to minor molecular antimicrobial systems, which have short-term functions and are poisonous. Although the mechanism of action of nanoparticles (NPs) is unknown, scientific suggestions include the oxidative-reductive phenomenon, reactive ionic metals, and reactive oxygen species (ROS). Many synchronized gene transformations in the same bacterial cell are essential for antibacterial resistance to emerge; thus, bacterial cells find it difficult to build resistance to nanoparticles. Therefore, nanomaterials are considered as advanced solution tools for the fields of medical science and allied health science. The current review emphasizes the importance of nanoparticles and various nanosized materials as antimicrobial agents based on their size, nature, etc.