Chronic intracellular infections caused by drug-resistant pathogens pose a challenge to the treatment of chronic osteomyelitis. Such treatment requires an intracellular delivery system for the sustained release of antibiotics such as vancomycin (VCM), which is an antibiotic of last resort used against many clinically resistant bacteria. In this work, we report VCM-loaded N-trimethyl chitosan (TMC) nanoparticles and their potential application for drug delivery. The results showed that the prepared nanoparticles were predominantly spherical in shape with an average particle diameter of 220 nm, a positive zeta potential, and a loading efficiency of 73.65% ± 1.83%. Furthermore, their drug release profile followed the Higuchi model for sustained release, with non-Fickian diffusion. Over a 24-h period, 6.51% ± 0.58% of the drug within the optimized nanoparticles was released. In vitro cytology showed that osteoblasts (OBs) exhibited higher alkaline phosphatase activity (ALP) after exposure to TMC nanoparticle material. Furthermore, TMC nanoparticles increased the uptake of water-soluble quantum dots (QDs) by OBs, and both nanoparticles and VCM/TMC mixtures improved OB proliferative activity. We also investigated the minimum inhibitory concentration (MIC, 60 μg/mL), half maximal inhibitory concentration (IC50, 48.47 μg/mL), diameter of inhibition zone (DIZ, 1.050 cm), and turbidimetric (TB) assay of nanoparticles. All data demonstrated that VCM/TMC nanoparticles had excellent antibacterial activity against the Gram-positive bacterium Staphylococcus aureus. These findings suggest that VCM-loaded TMC nanoparticles have good potential for the sustained delivery of antibiotics to bone infections.

Mannose polyethylenimine with a molecular weight of 25 k (Man-PEI_25k) was synthesized via a phenylisothiocyanate bridge using mannopyranosylphenyl isothiocyanate as a coupling reagent, and characterized by ¹H NMR (nuclear magnetic resonance) and FT-IR (Fourier transform infrared spectroscopy) analysis. Spherical nanoparticles were formed with diameters of 80–250 nm when the copolymer was mixed with DNA at various charge ratios of copolymer/DNA (N/P). Gel electrophoresis demonstrated that the DNA had been condensed and retained by the PEI derivates at low N/P ratios. The Man-PEI_25k/DNA complexes were less cytotoxic than the PEI complexes with a molecular weight of 25 k (PEI_25k) at the same N/P ratio. Laser scan confocal microscopy and flow cytometry confirmed that the Man-PEI_25k/DNA complexes gave higher cell uptake efficiency in (Dendritic cells) DC2.4 cells than HeLa cells. The transfection efficiency of Man-PEI_25k was higher than that of PEI_25k towards DC2.4 cells. These results indicated that Man-PEI_25k could be used as a potential DC-targeting non-viral vector for gene therapy.

Objective: The objective of this study was to examine the preparation process of DSPE-PEG-C60/NCTD micelles and assess the impact of fullerenol (C60)-modified micelles on the nephrotoxicity and antitumor activity of NCTD. Method: The micelles containing NCTD were prepared using the ultrasonic method and subsequently optimized and characterized. The cytotoxicity of micelles loaded with NCTD was assessed using the CCK-8 method on human hepatoma cell lines HepG2 and BEL-7402, as well as normal cell lines HK-2 and L02. Acridine orange/ethidium bromide (AO/EB) double staining and flow cytometry were employed to assess the impact of NCTD-loaded micelles on the apoptosis of the HK-2 cells and the HepG2 cells. Additionally, JC-1 fluorescence was utilized to quantify the alterations in mitochondrial membrane potential. The generation of reactive oxygen species (ROS) following micelle treatment was determined through 2′,7′-dichlorofluorescein diacetate (DCFDA) staining. Results: The particle size distribution of the DSPE-PEG-C60/NCTD micelles was determined to be 91.57 nm (PDI = 0.231). The zeta potential of the micelles was found to be −13.8 mV. The encapsulation efficiency was measured to be 91.9%. The in vitro release behavior of the micelles followed the Higuchi equation. Cellular experiments demonstrated a notable decrease in the toxicity of the C60-modified micelles against the HK-2 cells, accompanied by an augmented inhibitory effect on cancer cells. Compared to the free NCTD group, the DSPE-PEG-C60 micelles exhibited a decreased apoptosis rate (12%) for the HK-2 cell line, lower than the apoptosis rate observed in the NCTD group (36%) at an NCTD concentration of 75 μM. The rate of apoptosis in the HepG2 cells exhibited a significant increase (49%), surpassing the apoptosis rate observed in the NCTD group (24%) at a concentration of 150 μM NCTD. The HK-2 cells exhibited a reduction in intracellular ROS and an increase in mitochondrial membrane potential (ΔψM) upon exposure to C60-modified micelles compared to the NCTD group. Conclusions: The DSPE-PEG-C60/NCTD micelles, as prepared in this study, demonstrated the ability to decrease cytotoxicity and ROS levels in normal renal cells (HK-2) in vitro. Additionally, these micelles showed an enhanced antitumor activity against human hepatocellular carcinoma cells (HepG2, BEL-7402).

Objective: The aim of this study was to optimize the formulation of a C60-modified self-microemulsifying drug delivery system loaded with triptolide (C60-SMEDDS/TP) and evaluate the cytoprotective effect of the C60-SMEDDS/TP on normal human cells. Results: The C60-SMEDDS/TP exhibited rapid emulsification, an optimal particle size distribution of 50 ± 0.19 nm (PDI 0.211 ± 0.049), and a near-neutral zeta potential of −1.60 mV. The release kinetics of TP from the C60-SMEDDS/TP exhibited a sustained release profile and followed pseudo-first-order release kinetics. Cellular proliferation and apoptosis analysis indicated that the C60-SMEDDS/TP (with a mass ratio of TP: DSPE-PEG-C60 = 1:10) exhibited lower toxicity towards L02 and GES-1 cells. This was demonstrated by a higher IC50 (40.88 nM on L02 cells and 17.22 nM on GES-1 cells) compared to free TP (21.3 nM and 11.1 nM), and a lower apoptosis rate (20.8% on L02 cells and 26.3% on GES-1 cells, respectively) compared to free TP (50.5% and 47.0%) at a concentration of 50 nM. In comparison to the free TP group, L02 cells and GES-1 cells exposed to the C60-SMEDDS/TP exhibited a significant decrease in intracellular ROS and an increase in mitochondrial membrane potential (ΔψM). On the other hand, the C60-SMEDDS/TP demonstrated a similar inhibitory effect on BEL-7402 cells (IC50 = 28.9 nM) and HepG2 cells (IC50 = 107.6 nM), comparable to that of the free TP (27.2 nM and 90.4 nM). The C60-SMEDDS/TP group also exhibited a similar intracellular level of ROS and mitochondrial membrane potential compared to the SMEDDS/TP and free TP groups. Method: Fullerenol-Grafted Distearoyl Phosphatidylethanolamine-Polyethylene Glycol (DSPE-PEG-C60) was synthesized and applied in the self-microemulsifying drug delivery system. The C60-SMEDDS/TP was formulated using Cremophor EL, medium-chain triglycerides (MCT), PEG-400, and DSPE-PEG-C60, and loaded with triptolide (TP). The toxicity and bioactivity of the C60-SMEDDS/TP were assessed using normal human liver cell lines (L02 cells), normal human gastric mucosal epithelial cell lines (GES-1 cells), and liver cancer cell lines (BEL-7402 cells and HepG2 cells). The production of reactive oxygen species (ROS) after the C60-SMEDDS/TP treatment was assessed using 2′,7′-dichlorofluorescein diacetate (DCFDA) staining. The alterations in mitochondrial membrane potential (ΔψM) were assessed by measuring JC-1 fluorescence. Conclusions: The cytoprotection provided by the C60-SMEDDS/TP favored normal cells (L02 and GES-1) over tumor cells (BEL-7402 and HepG2 cells) in vitro. This suggests a promising approach for the safe and effective treatment of TP.

Objective: To investigate the therapeutic effects of the PRAC on acute liver injury and its potential as an ingredient in drugs and nutraceuticals.Methods: Microwave-assisted extraction technology combined with Box-Behnken model combined with the three kinds of artificial neural networks was used to optimize PRAC extraction process. Characterize the structure and composition of PRAC. In order to prevent PRAC from being degraded by the gastrointestinal environment, PRAC-loaded liposomes were fabricated. The efficacy of PRAC-loaded liposomes was evaluated by three acute liver injury animal models prepared according to different mechanisms.Results: The best yield of PRAC was 4.49%, and the purity reached up to 86.53% by optimizing the microwave parameters using Box-Behnken model combined with the three kinds of artificial neural networks. PRAC was characterized as a galactan having a backbone consisting predominately of →4)-D-Galp-(1→ and →4)-D-Glcp-(1→ with a molecular weight of 12.713 kDa. The PRAC-loaded liposome obtained had a size about 340 nm with a polydispersity index 0.234. The entrapment efficiency was 70.12% and the drug loading was 1.24%. Liposomes can be fully released in the gastrointestinal environment within 12 h and have long-term stability at 4°C. The therapeutic effect of PRAC liposomes on acute liver injury was confirmed by three animal models of acute liver injury.Conclusion: PRAC is a potential drug for the treatment of acute liver injury.