Osteoinductive Dental Pulp Stem Cell-Derived Extracellular Vesicle-Loaded Multifunctional Hydrogel for Bone Regeneration.

Stem cell-derived extracellular vesicles (EVs) show great potential for promoting bone tissue regeneration. However, normal EVs (Nor-EVs) have a limited ability to direct tissue-specific regeneration. Therefore, it is necessary to optimize the osteogenic capacity of EV-based systems for repairing extensive bone defects. Herein, we show that hydrogels loaded with osteoinductive dental pulp stem cell-derived EVs (Ost-EVs) enhanced bone tissue remodeling, resulting in a 2.23 ± 0.25-fold increase in the expression of bone morphogenetic protein 2 (BMP2) compared to the hydrogel control group. Moreover, Ost-EVs led to a higher expression of alkaline phosphatase (ALP) (1.88 ± 0.16 of Ost-EVs relative to Nor-EVs) and the formation of orange-red calcium nodules (1.38 ± 0.10 of Ost-EVs relative to Nor-EVs) in vitro. RNA sequencing revealed that Ost-EVs showed significantly high miR-1246 expression. An ideal hydrogel implant should also adhere to surrounding moist tissues. In this study, we were drawn to mussel-inspired adhesive modification, where the hydrogel carrier was crafted from hyaluronic acid (HA) and polyethylene glycol derivatives, showcasing impressive tissue adhesion, self-healing capabilities, and the ability to promote bone growth. The modified HA (mHA) hydrogel was also responsive to environmental stimuli, making it an effective carrier for delivering EVs. In an ectopic osteogenesis animal model, the Ost-EV/hydrogel system effectively alleviated inflammation, accelerated revascularization, and promoted tissue mineralization. We further used a rat femoral condyle defect model to evaluate the in situ osteogenic ability of the Ost-EVs/hydrogel system. Collectively, our results suggest that Ost-EVs combined with biomaterial-based hydrogels hold promising potential for treating bone defects.

Hepatocyte-targeted delivery using oleanolic acid-loaded liposomes for enhanced hepatocellular carcinoma therapy.

Drug-loaded liposomes have been shown to be effective in the treatment of hepatocellular carcinoma (HCC). However, the systemic non-specific distribution of drug-loaded liposomes in tumor patients is a critical therapeutic challenge. To address this issue, we developed galactosylated chitosan-modified liposomes (GC@Lipo) that could selectively bind to the asialoglycoprotein receptor (ASGPR), which is highly expressed on the membrane surface of HCC cells. Our study demonstrated that the GC@Lipo significantly enhanced the anti-tumor efficacy of oleanolic acid (OA) by enabling targeted drug delivery to hepatocytes. Remarkably, treatment with OA-loaded GC@Lipo inhibited the migration and proliferation of mouse Hepa1-6 cells by upregulating E-cadherin expression and downregulating N-cadherin, vimentin, and AXL expressions, compared to a free OA solution and OA-loaded liposomes. Furthermore, using an axillary tumor xenograft mouse model, we observed that OA-loaded GC@Lipo led to a significant reduction in tumor progression, accompanied by concentrated enrichment in hepatocytes. These findings strongly support the clinical translation of ASGPR-targeted liposomes for the treatment of HCC.

Bone marrow mesenchymal stem cell sheets with high expression of hBD3 and CTGF promote periodontal regeneration.

The multi-bacterial environment of the oral cavity makes it hard for periodontal regeneration. As a class of antimicrobial peptide, beta defensin has been found to show broad-spectrum antibacterial ability. In addition, connective tissue growth factor (CTGF) is demonstrated to play a great role in multi-physiological events such as angiogenesis, wound healing and, more importantly, fibrogenesis. In this study, human ß defensin 3 (hBD3) and CTGF were co-transfected into bone marrow derived mesenchymal stem cells (BMSCs) for preparing cell sheets. The transfection efficiency was detected through fluorescence of eGFP and western blot assay. Our results showed that the hBD3 and CTGF proteins were highly and stably expressed in the BMSCs after transfection. The results of RT-PCR and induced differentiation indicated that hBD3 promoted osteogenic differentiation of BMSCs, while CTGF significantly increased fibrogenic differentiation even in the presence of hBD3. The BMSCs acquired stronger capacity in terms of promoting M2 polarization of RAW 264.7 macrophages fulfilled by the transfection and secretion of hBD3 and CTGF. To further evaluate the periodontal remodeling performance of cell sheets, a coralline hydroxyapatite (CHA)-chitosan based hydrogel-human tooth system was designed to simulate the natural periodontal environment. The results showed that dense extracellular matrix, oriented fiber arrangement, and abundant collagen deposition appeared in the area of BMSCs sheets after subcutaneous transplantation. Altogether, our data showed that the lentivirus transfected BMSCs sheets had a promising application prospect for periodontal repair.

Quercetin loaded liposomes modified with galactosylated chitosan prevent LPS/D-GalN induced acute liver injury.

Quercetin (Que) has been proved to have various biological activities, including anti-oxidation, anti-inflammation and anti-virus, showing great potential in liver protection. However, its water insolubility leads to low bioavailability. Therefore, the development of a suitable drug delivery fashion is imminent. In recent years, liposomes have been widely used in the fields of drug delivery and gene transfer thanks to the cell membrane like structure, easy surface-modification and high encapsulation efficiency. Herein, we fabricated Que loaded anionic liposomes. Galactosylated chitosan (GC) was simply attached to the surfaces of liposomes through electrostatic adsorption to achieve targeted delivery by binding to asialoglycoprotein receptor (ASGPR). The results showed that Que loaded liposomes modified with GC (GC-Que-Lipo) could enrich the liver in mice through tail vein injection. Liposomes could achieve sustained drug release and GC-Que-Lipo promoted M2 polarization of macrophages. More importantly, it could maintain low content of AST, ALT, ALP and high level of GSH while reducing lipid oxidation, thereby protecting the liver from damage in acute liver injury model. In general, we expect to be able to acquire targeted and efficient delivery of quercetin through a facile approach, thus fulfill the prevention and treatment of liver diseases.