Chikusetsu Saponin IVa liposomes modified with a retro-enantio peptide penetrating the blood-brain barrier to suppress pyroptosis in acute ischemic stroke rats.

BACKGROUND: The therapeutic strategies for acute ischemic stroke were faced with substantial constraints, emphasizing the necessity to safeguard neuronal cells during cerebral ischemia to reduce neurological impairments and enhance recovery outcomes. Despite its potential as a neuroprotective agent in stroke treatment, Chikusetsu saponin IVa encounters numerous challenges in clinical application. RESULT: Brain-targeted liposomes modified with THRre peptides showed substantial uptake by bEnd. 3 and PC-12 cells and demonstrated the ability to cross an in vitro blood-brain barrier model, subsequently accumulating in PC-12 cells. In vivo, they could significantly accumulate in rat brain. Treatment with C-IVa-LPs-THRre notably reduced the expression of proteins in the P2RX7/NLRP3/Caspase-1 pathway and inflammatory factors. This was evidenced by decreased cerebral infarct size and improved neurological function in MCAO rats. CONCLUSION: The findings indicate that C-IVa-LPs-THRre could serve as a promising strategy for targeting cerebral ischemia. This approach enhances drug concentration in the brain, mitigates pyroptosis, and improves the neuroinflammatory response associated with stroke.

Real-time fluorescence tracking of gene delivery via multifunctional nanocomposites.

Fluorescence imaging of transduced cells and tissues is valuable in the development of gene vectors and the evaluation of gene therapy efficacy. We report here the simple and rational design of multifunctional nanocomposites (NCs) for simultaneous gene delivery and fluorescence tracking based on ZnS:Mn(2+) quantum dots (QDs) and positively charged polymer coating. The positively charged imidazole in the as-synthesized amphiphilic copolymer can be used for gene loading via electrostatic interaction. While the introduced poly(ethylene glycol) (PEG) can be used to reduce the binding of plasma proteins to nanovectors and minimize clearance by the reticuloendothelial system after intravenous administration. Most importantly, these multifunctional nanovectors showed much lower cellular toxicity than the commercial polyethylenimine (PEI) transfection vectors. On the basis of the red fluorescence of QDs, we can real-time track the gene delivery in cells, and the transfection efficacy of pDNA encoding enhanced green fluorescence protein (pEGFP) was monitored via the green fluorescence of the GFP expressed by the pDNA delivered into the nuclei. Fluorescence imaging analysis confirmed that the QDs-based nanovectors delivered pDNA into HepG2 cells efficiently. These new insights and capabilities pave a new way toward nanocomposite engineering for fluorescence imaging tracking of gene therapy.

Astrocytes and microglia-targeted Danshensu liposomes enhance the therapeutic effects on cerebral ischemia-reperfusion injury.

Cerebral ischemia-reperfusion injury (CI/RI) is the main cause of disability and death in stroke without satisfactory therapeutic effect. Inflammation mediated by activation of astrocytes and microglia is the main pathological mechanism of CI/RI. Danshensu (DSS) has been shown to exert anti-inflammatory effects against brain injury. However, limited by its poor cellular permeability and low bioavailability, it is still needed the new DSS preparations with the ability to cross the blood-brain barrier (BBB) and target inflammatory glial cells. In this study, we developed phosphatidylserine (PS) and transferrin (TF) modified liposomes carrying DSS (TF/PS/DSS-LPs) to improve the therapeutic efficacy against ischemic stroke. First, TF molecules targeted transferrin receptor (TfR) that is overexpressed in the BBB. Following the liposomes enter the brain, PS modification allowed the liposomes to target and bind to the overexpressed phosphatidylserine-specific receptors (PSRs) on the surface of astrocytes and microglia. Furthermore, it enhanced the uptake of TF/PS/DSS-LPs by astrocytes and microglia, while polarizing astrocytes from A1 to A2 and microglia from M1 to M2, reducing neuronal inflammation, and ultimately ameliorating cerebral ischemic injury. Thus, TF/PS/DSS-LPs could potentially serve as a promising strategy for the CI/RI treatment.

Nanoparticle BAF312@CaP-NP Overcomes Sphingosine-1-Phosphate Receptor-1-Mediated Chemoresistance Through Inhibiting S1PR1/P-STAT3 Axis in Ovarian Carcinoma.

PURPOSE: Platinum/paclitaxel-based chemotherapy is the strategy for ovarian cancer, but chemoresistance, inherent or acquired, occurs and hinders therapy. Therefore, further understanding of the mechanisms of drug resistance and adoption of novel therapeutic strategies are urgently needed. METHODS: In this study, we report that sphingosine-1-phosphate receptor-1 (S1PR1)-mediated chemoresistance for ovarian cancer. Then we developed nanoparticles with a hydrophilic PEG2000 chain and a hydrophobic DSPE and biodegradable CaP (calcium ions and phosphate ions) shell with pH sensitivity as a delivery system (CaP-NPs) to carry BAF312, a selective antagonist of S1PR1 (BAF312@CaP-NPs), to overcome the cisplatin (DDP) resistance of the ovarian cancer cell line SKOV3DR. RESULTS: We found that S1PR1 affected acquired chemoresistance in ovarian cancer by increasing the phosphorylated-signal transduction and activators of transcription 3 (P-STAT3) level. The mean size and zeta potential of BAF312@CaP-NPs were 116 ± 4.341 nm and -9.67 ± 0.935 mV, respectively. The incorporation efficiency for BAF312 in the CaP-NPs was 76.1%. The small size of the nanoparticles elevated their enrichment in the tumor, and the degradable CaP shell with smart pH sensitivity of the BAF312@CaP-NPs ensured the release of BAF312 in the acidic tumor niche. BAF312@CaP-NPs caused substantial cytotoxicity in DDP-resistant ovarian cancer cells by downregulating S1PR1 and P-STAT3 levels. CONCLUSION: We found that BAF312@CaP-NPs act as an effective and selective delivery system for overcoming S1PR1-mediated chemoresistance in ovarian carcinoma by inhibiting S1PR1 and P-STAT3.

Enhanced therapeutic effect of Adriamycin on multidrug resistant breast cancer by the ABCG2-siRNA loaded polymeric nanoparticles assisted with ultrasound.

The overexpression of the breast cancer resistance protein (ABCG2) confers resistance to Adriamycin (ADR) in breast cancer. The silencing of ABCG2 using small interfering RNA (siRNA) could be a promising approach to overcome multidrug resistance (MDR) in cancer cells. To deliver ABCG2-siRNA effectively into breast cancer cells, we used mPEG-PLGA-PLL (PEAL) nanoparticles (NPs) with ultrasound-targeted microbubble destruction (UTMD). PEAL NPs were prepared with an emulsion-solvent evaporation method. The NPs size was about 131.5 ± 6.5 nm. The siRNA stability in serum was enhanced. The intracellular ADR concentration increased after the introduction of siRNA-loaded NPs. After intravenous injection of PEAL NPs in tumor-bearing mice, the ABCG2-siRNA-loaded NPs with UTMD efficiently silenced the ABCG2 gene and enhanced the ADR susceptibility of MCF-7/ADR (ADR resistant human breast cancer cells). The siRNA-loaded NPs with UTMD + ADR showed better tumor inhibition effect and good safety in vivo. These results indicate that ADR-chemotherapy in combination with ABCG2-siRNA is an attractive strategy to treat breast cancer.

Enhanced delivery of PEAL nanoparticles with ultrasound targeted microbubble destruction mediated siRNA transfection in human MCF-7/S and MCF-7/ADR cells in vitro.

The gene knockdown activity of small interfering RNA (siRNA) has led to their use as potential therapeutics for a variety of diseases. However, successful gene therapy requires safe and efficient delivery systems. In this study, we choose mPEG-PLGA-PLL nanoparticles (PEAL NPs) with ultrasound targeted microbubble destruction (UTMD) to efficiently deliver siRNA into cells. An emulsification-solvent evaporation method was used to prepare siRNA-loaded PEAL NPs. The NPs possessed an average size of 132.6±10.3 nm (n=5), with a uniform spherical shape, and had an encapsulation efficiency (EE) of more than 98%. As demonstrated by MTT assay, neither PEAL NPs nor siRNA-loaded PEAL NPs showed cytotoxicity even at high concentrations. The results of cellular uptake showed, with the assistance of UTMD, the siRNA-loaded PEAL NPs can be effectively internalized and can subsequently release siRNA in cells. Taken together, PEAL NPs with UTMD may be highly promising for siRNA delivery, making it possible to fully exploit the potential of siRNA-based therapeutics.

Design and in vitro/in vivo evaluation of multi-layer film coated pellets for omeprazole.

The purpose of the study is to perform the in vitro and in vivo evaluation of multi-layer film coatings for omeprazole. The system consists of drug-layered or drug-containing core pellets coated with salt (sodium chloride and disodium hydrogen phosphate), hydroxypropyl methyl cellulose (HPMC), and enteric film-coating layer, respectively. The drug-layered core pellets were prepared by a coating layer of omeprazole on inert pellet cores in fluidized bed coater. An in vitro/in vivo gastro-resistance study was conducted, and a dissolution study was performed in pH 7.4 phosphate buffer for omeprazole release. The multi-layer coated pellets were stable in gastric pH conditions and upper gastrointestinal (GI) tract in rats. Salt layer improved the drug stability, and its coating levels had little influence on the dissolution profiles of omeprazole. The rate of drug release was significantly delayed by HPMC layer. The salt layer could function as a separated layer, and substitute part of the HPMC layer and decrease the coating levels of HPMC. The bioavailability (AUC) of the multi-layer coated drug-layered and drug-containing pellets was 3.48+/-0.86 and 2.97+/-0.57 microg*h/ml, respectively. The drug-layered pellets with multi-layer film coatings not only provided delayed and rapid release of omeprazole, but also could provide a good stable property for omeprazole. It was confirmed that rapid in vitro drug release rate resulted in better absorption.

Biphasic drug release: permeability and swelling of pectin/ethylcellulose films, and in vitro and in vivo correlation of film-coated pellets in dogs.

The major objectives of this study were i) to evaluate the permeability and swelling characteristics of isolated films prepared by mixing of pectin with ethylcellulose; and ii) to assess the absorption and in vitro/in vivo correlation (IVIVC) of 5-FU film-coated colon-targeted pellets in dogs. Free films were prepared by casting and solvent evaporation method. These free films were evaluated by swelling experiment and permeability to 5-FU in different media. Pectin/ethylcellulose films had suitable characteristics for colonic delivery; and when the addition of pectin was up to the ratio of 30%, the swelling and permeability of the mixed films was significantly increased in the simulated colonic fluid (SCF). Pharmacokinetic study in dogs gave Tmax/Cmax of 14 h/1.6 microg/ml and 16 h/1.7 microg/ml for total weight gain (TWG)-22% and 18% coated pellets, respectively. The plasma 5-FU levels of the TWG-22% and 18% coated pellets were maintained at a much lower level with a mean residence time (MRT) of 18-20 h, longer than 2.1 h for 5-FU uncoated pellets, confirming delayed absorption. There was no statistically significant difference in the area under the plasma concentration vs. times curve (AUC) values between the uncoated pellets and the coated pellets. Moreover, a good linear regression relationship was observed between the percent in vitro dissolution in SCF and the percent absorption or percent AUC. It was concluded that i) pectin within the mixed films were susceptible to colonic enzymes, and the film-coated pellets are potentially useful for colonic drug delivery; and ii) in vitro dissolution testing in SCF could be used to establish certain IVIVC for the colon-specific drug delivery systems activated by microflora.