Cutting-Edge HEK293T Protein-Integrated Lipid Nanostructures: Boosting Biocompatibility and Efficacy.

Recently, artificial exosomes have been developed to overcome the challenges of natural exosomes, such as production scalability and stability. In the production of artificial exosomes, the incorporation of membrane proteins into lipid nanostructures is emerging as a notable approach for enhancing biocompatibility and treatment efficacy. This study focuses on incorporating HEK293T cell-derived membrane proteins into liposomes to create membrane-protein-bound liposomes (MPLCs), with the goal of improving their effectiveness as anticancer therapeutics. MPLCs were generated by combining two key elements: lipid components that are identical to those in conventional liposomes (CLs) and membrane protein components uniquely derived from HEK293T cells. An extensive comparison of CLs and MPLCs was conducted across multiple in vitro and in vivo cancer models, employing advanced techniques such as cryo-TEM (tramsmission electron microscopy) imaging and FT-IR (fourier transform infrared spectroscopy). MPLCs displayed superior membrane fusion capabilities in cancer cell lines, with significantly higher cellular uptake. Additionally, MPLCs maintained their morphology and size better than CLs when exposed to FBS (fetal bovine serum), suggesting enhanced serum stability. In a xenograft mouse model using HeLa and ASPC cancer cells, intravenous administration of MPLCs MPLCs accumulated more in tumor tissues, highlighting their potential for targeted cancer therapy. Overall, these results indicate that MPLCs have superior tumor-targeting properties, possibly attributable to their membrane protein composition, offering promising prospects for enhancing drug delivery efficiency in cancer treatments. This research could offer new clinical application opportunities, as it uses MPLCs with membrane proteins from HEK293T cells, which are known for their efficient production and compatibility with GMP (good manufacturing practice) standards.

Arginine modified PAMAM dendrimer for interferon beta gene delivery to malignant glioma.

A xenograft brain tumor model was established by the subcutaneous injection of U87MG cells into nude mice to investigate the efficacy of a non-viral vector, arginine-modified polyamidoamine dendrimer (PAMAM-R), in delivering a therapeutic gene, human interferon beta (IFN-ß). We used 4',6-diamidino-2-phenylindole staining, the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay, and the caspase-3 activity assay to determine the induction of apoptosis upon transfection with the PAMAM-R/IFN-ß gene polyplex in vitro. The polyplex was injected into xenograft brain tumors. Mice treated with PAMAM-R/pORF-IFN-ß exhibited a significantly smaller tumor size than control mice and PAMAM-R/pORF treated mice. Hematoxylin/eosin staining and immunohistochemistry with the endothelial growth factor receptor antibody also revealed inhibition of tumor growth. Furthermore, reverse transcription polymerase chain reaction and the TUNEL assay also verified the expression of IFN-ß and induction of apoptosis in vivo. These results indicate that the PAMAM-R/pORF-IFN-ß polyplex is an effective therapeutic candidate for glioblastoma multiforme due to its selective induction of apoptosis in tumor cells.

Paclitaxel coating of the luminal surface of hemodialysis grafts with effective suppression of neointimal hyperplasia.

OBJECTIVES: Paclitaxel coating of hemodialysis grafts is effective in suppressing neointimal hyperplasia in the graft and vascular anastomosis sites. However, paclitaxel can have unwanted effects on the surrounding tissues. To reduce such problems, we developed a method to coat the drug only on the luminal surface of the graft, with little loading on the outer surface. METHODS: A peristaltic pump and a double-solvent (water and acetone) system were used to achieve an inner coating of paclitaxel. At the ratio of 90% acetone, paclitaxel was homogeneously coated only on the luminal surface of the graft without changing the physical properties. To determine its effect, grafts were implanted between the common carotid artery and the external jugular vein in pigs using uncoated control grafts (n = 6) and low-dose (n = 6, 0.22 µg/mm(2)) and high-dose (n = 6, 0.69 µg/mm(2)) paclitaxel inner-coated grafts. Cross-sections of graft-venous anastomoses were analyzed histomorphometrically 6 weeks after placement to measure the patency rate, percentage of luminal stenosis, and neointimal area. RESULTS: No signs of infection or bacterial contamination were observed in the paclitaxel inner-coated groups. Only one of the six control grafts was patent, but all of the paclitaxel-coated grafts were patent, with little neointima. The mean ± standard error values of percentage luminal stenosis were 75.7% ± 12.7% (control), 17.5% ± 3.1% (low dose), and 19.7% ± 3.0% (high dose). The values for the neointimal area (in mm(2)) were 8.77 ± 1.66 (control), 3.53 ± 0.73 (lose dose), and 4.24 ± 0.99 (high dose). Compared with the control group, paclitaxel inner-coated vascular grafts significantly suppressed neointimal hyperplasia (low dose, P = .001; high dose, P = .002). Myofibroblast proliferation and migration into the graft interstices confirmed the firm attachment of the implanted graft to the surrounding tissue. CONCLUSIONS: Paclitaxel coating on the inner luminal surface of vascular grafts was effective in suppressing neointimal hyperplasia, with little inhibition of myofibroblast infiltration within the graft wall.

Suppression of neointimal hyperplasia by sirolimus-eluting expanded polytetrafluoroethylene (ePTFE) haemodialysis grafts in comparison with paclitaxel-coated grafts.

BACKGROUND: Haemodialysis vascular access dysfunction caused by aggressive venous neointimal hyperplasia is a major problem for haemodialysis patients with synthetic arteriovenous (AV) grafts. Several different strategies to prevent venous stenosis by inhibiting smooth muscle cell proliferation and migration using local delivery of potent antiproliferative agents are currently under investigation. We performed this study to evaluate the efficacy of sirolimus-eluting vascular grafts in preventing stenosis and to compare the effectiveness of sirolimus-coated grafts with that of paclitaxel-coated vascular grafts that we characterized in a previous study. METHODS: AV grafts were implanted laterally between the common carotid artery and external jugular vein of 14 female Landrace pigs. Three types of grafts were implanted: grafts coated with 1.08 µg/mm(2) sirolimus (low dose, n = 6), grafts coated with 2.41 µg/mm(2) sirolimus (high dose, n = 2) and uncoated control grafts (n = 6). Animals were sacrificed 6 weeks after surgery. Cross-sections of the venous anastomoses were analysed to determine the percentage of luminal stenosis in each group, and immunohistochemistry was performed to identify the cellular phenotypes of the neointimal hyperplasia and tissues adjacent to the implanted grafts. RESULTS: Compared with the control group, neointimal hyperplasia in the venous anastomoses of the groups implanted with sirolimus-coated vascular grafts was significantly suppressed without infection. The mean ± standard error values for the percentage of luminal stenosis were 75.7 ± 12.7% in the control group and 22.2 ± 1.41% in the low-dose sirolimus-coated group. Myofibroblasts and fibroblasts were the major cell types found in the neointimal hyperplasia. CONCLUSIONS: Neointimal hyperplasia was effectively suppressed by sirolimus-eluting grafts. However, the inhibitory effects of sirolimus-eluting grafts were weaker than those observed for paclitaxel-coated grafts in our previous study.

Comparison between arginine conjugated PAMAM dendrimers with structural diversity for gene delivery systems.

Mono- and di-arginine conjugated PAMAM dendrimers (G=3 or 4) were synthesized to examine the structure-activity relationships of arginine conjugation for gene delivery systems. Number of conjugated arginines was examined by 1H NMR (PAMAM3-R: 31, PAMAM4-R: 60, PAMAM3-R2: 59, PAMAM4-R2: 116). They could retard pDNA at a charge ratio of 2 and form polyplexes with sizes less than 250 nm from a charge ratio of 4. Di-arginine conjugated dendrimers showed higher Zeta-potential values and polyplex stabilities than mono-arginine conjugates. PAMAM3-R and PAMAM4-R showed low cytotoxicities even at high concentration but PAMAM3-R2 and PAMAM4-R2 exhibited significant cytotoxicities at high concentration. PAMAM3-R2 displayed greater transfection efficiency than PAMAM3-R, although the transfection efficiency of PAMAM4-R2 was not higher than that of PAMAM4-R in all condition. PAMAM3-R2 and PAMAM4-R2 polyplexes were observed to show the good intra-nuclear localization in comparison with PAMAM3-R and PAMAM4-R. It is concluded that di-arginine conjugation to PAMAM dendrimers can improve polyplex stability, intra-nuclear localization, and transfection efficiency but also induce charge density- and generation-dependent cytotoxicity. Therefore, a novel strategy for highly densed arginine conjugation maintaining low cytotoxicity will be needed for the development of efficient gene delivery carriers.