Quangang Zhu

Second-generation aptamer-conjugated PSMA-targeted delivery system for prostate cancer therapy

Background: miR-15a and miR-16-1 have been identified as tumor suppressor genes in prostate cancer, but their safe and effective delivery to target cells is key to the successful use of this therapeutic strategy. RNA aptamer A10 has been used as a ligand, targeting prostate cancer cells that express prostate-specific membrane antigen (PSMA). Compared with A10, the binding of the second-generation RNA aptamer, A10-3.2, to PSMA is more efficient. Methods: A10-3.2 was investigated as a PSMA-targeting ligand in the design of a polyamidoamine (PAMAM)-based microRNA (miR-15a and miR-16-1) vector to prostate cancer cells. Using polyethyleneglycol (PEG) as a spacer, PAMAM was conjugated to aptamer (PAMAM-PEG-APT) and used as a vehicle for miRNA target delivery. Results: Luciferase assays of pGL-3 expression against PC3 (PSMA−) and LNCaP (PSMA+) cells demonstrated that the transfection efficiency of the synthesized DNA/PAMAM-PEG-APT complex was higher than that of the DNA/PAMAM-PEG complex. In addition, cell viability assays of LNCaP (PSMA+) cells showed that, with a N/P ratio of 15:1, the IC50 value of miRNA/PAMAM-PEG-APT was approximately 4.7-fold lower than that of miRNA/PAMAM-PEG. Conclusion: This PSMA-targeted system may prove useful in widening the therapeutic window and allow for selective killing of prostate cancer cells.

Penetration and distribution of PLGA nanoparticles in the human skin treated with microneedles.

This study was designed to investigate the penetration and the distribution of poly(d,l-lactic-co-glycolic acid) (PLGA) nanoparticles in the human skin treated with microneedles. Fluorescent nanoparticles were prepared to indicate the transdermal transport process of the nanoparticles. Permeation study was performed on Franz-type diffusion cells in vitro. The distribution of nanoparticles was visualized by confocal laser scanning microscopy (CLSM) and quantified by high performance liquid chromatography (HPLC). CLSM images showed that nanoparticles were delivered into the microconduits created by microneedles and permeated into the epidermis and the dermis. The quantitative determination showed that (i) the permeation of nanoparticles into the skin was enhanced by microneedles, but no nanoparticle reached the receptor solution; (ii) much more nanoparticles deposited in the epidermis than those in the dermis; (iii) the permeation was in a particle size-dependent manner; and (iv) the permeation increased with the nanoparticle concentration increasing until a limit value was reached. These results suggested that microneedles could enhance the intradermal delivery of PLGA nanoparticles. The biodegradable nanoparticles would sustain drug release in the skin and supply the skin with drug over a prolonged period. This strategy would prove to be useful for topical drug administration.

Substance P receptor expression in human skin keratinocytes and fibroblasts

Background  There is increasing evidence that neuropeptides, especially substance P (SP), may be involved in the pathogenesis of cutaneous allergic inflammation (CAI).

Strong cellular and humoral immune responses induced by transcutaneous immunization with HBsAg DNA-cationic deformable liposome complex.

Abstract:  Transcutaneous immunization presents a major challenge on account of poor permeability of antigens through the skin barrier. To overcome this limitation, the deformable liposome could be a better method for transcutaneous delivery of these antigens. In this study, hepatitis B surface antigen (HBsAg) plasmid DNA–cationic complex deformable liposome was utilized as a mode for enhanced immunity against the antigen. Deformable liposome was prepared by conventional rotary evaporation method and characterized for various parameters such as vesicles shape and surface morphology, size and size distribution, entrapment efficiency, elasticity and stability. The immune stimulating activity was studied by measuring serum anti‐HBsAg titre and cytokines level (interleukin‐4 and interferon‐γ) following topical application of liposome in BALB/c mice and results were compared with deformable liposome encapsulated DNA applied topically as well as naked DNA and pure recombinant HBsAg, administered intramuscularly. It was observed that deformable liposome elicited a comparable serum antibody titre and endogenous cytokines levels compared to other vaccinations. The study signifies the potential of deformable liposome as DNA vaccine carriers for effective transcutaneous immunization.

Degradable gene delivery systems based on Pluronics-modified low-molecular-weight polyethylenimine: preparation, characterization, intracellular trafficking, and cellular distribution

Background Cationic copolymers consisting of polycations linked to nonionic amphiphilic block polymers have been evaluated as nonviral gene delivery systems, and a large number of different polymers and copolymers of linear, branched, and dendrimeric architectures have been tested in terms of their suitability and efficacy for in vitro and in vivo transfection. However, the discovery of new potent materials still largely relies on empiric approaches rather than a rational design. The authors investigated the relationship between the polymers’ structures and their biological performance, including DNA compaction, toxicity, transfection efficiency, and the effect of cellular uptake. Methods This article reports the synthesis and characterization of a series of cationic copolymers obtained by grafting polyethyleneimine with nonionic amphiphilic surfactant polyether-Pluronic® consisting of hydrophilic ethylene oxide and hydrophobic propylene oxide blocks. Transgene expression, cytotoxicity, localization of plasmids, and cellular uptake of these copolymers were evaluated following in vitro transfection of HeLa cell lines with various individual components of the copolymers. Results Pluronics can exhibit biological activity including effects on enhancing DNA cellular uptake, nuclear translocation, and gene expression. The Pluronics with a higher hydrophilic-lipophilic balance value lead to homogeneous distribution in the cytoplasm; those with a lower hydrophilic-lipophilic balance value prefer to localize in the nucleus. Conclusion This Pluronic-polyethyleneimine system may be worth exploring as components in the cationic copolymers as the DNA or small interfering RNA/microRNA delivery system in the near future.

Anti-DR5 monoclonal antibody-mediated DTIC-loaded nanoparticles combining chemotherapy and immunotherapy for malignant melanoma: target formulation development and in vitro anticancer activity

Background The increased incidence of malignant melanoma in recent decades, along with its high mortality rate and pronounced resistance to therapy pose an enormous challenge. Novel therapeutic strategies, such as immunotherapy and targeted therapy, are urgently needed for melanoma. In this study, a new active targeting drug delivery system was constructed to combine chemotherapy and active specific immunotherapy. Methods The chemotherapeutic drug, dacarbazine (DTIC), that induces apoptosis through the intrinsic pathway which typically responds to severe DNA damage, was used as a model drug to prepare DTIC-loaded polylactic acid (PLA) nanoparticles (DTIC-NPs), which were covalently conjugated to a highly specific targeting functional TRAIL-receptor 2 (DR5) monoclonal antibody (mAb) that can contribute directly to cancer cell apoptosis or growth inhibition through the extrinsic pathway. Results Our in vitro experiments demonstrated that DTIC-PLA-DR5 mAb nanoparticles (DTIC-NPs-DR5 mAb) are an active targeting drug delivery system which can specifically target DR5-overexpressing malignant melanoma cells and become efficiently internalized. Most strikingly, compared with conventional DTIC-NPs, DTIC-NPs-DR5 mAb showed significantly enhanced cytotoxicity and increased cell apoptosis in DR5-positive malignant melanoma cells. Conclusion The DTIC-NPs-DR5 mAb described in this paper might be a potential formulation for targeting chemotherapy and immunotherapy to DR5-overexpressing metastatic melanoma.

Biodegradable stearylated peptide with internal disulfide bonds for efficient delivery of siRNA in vitro and in vivo.

RNA-based delivery system for cancer therapy remains a challenge. In this study, a stearyl-peptide (SHR) was synthesized using arginine, histidine, cysteine, and stearyl moieties. Further, the stearyl-peptides were cross-linked by disulfide bonds to obtain cross-linked polypeptides (SHRss) with different molecular weight (SHRss1, SHRss2, SHRss3, SHRss4). The SHRss could effectively condense small interfering RNA (siRNA) into polyplexes with a hydrodynamic size of 100-300 nm and zeta potential of 20-40 mV. Flow cytometry and confocal laser scanning microscope studies revealed high cellular uptake and rapid dissociation behavior of SHRss2/siRNA complexes. Long-lasting high concentration of siRNA in cytoplasm was observed even at 24 h after SHRss2/Cy3-siRNA transfection. Compared with SHR, the SHRss showed much improved siRNA interference efficiency targeting luciferase on Luc-Hela cells. Moreover, SHRss2 exhibited higher interference efficiency and slower decay rate on Luc-Hela cells than Lipofectamine 2000 and SHR. In addition, much weaker expression of red fluorescence protein was also observed on SHRss2/simCh-treated mCherry-HEK293 cells than Lipofectamine 2000 and SHR. The SHRss did not induce cytotoxicity at siRNA concentrations of 25-200 nM under transfection. The in vivo studies demonstrated the gene interference efficiency of SHRss2/siRNA complexes. Our studies indicated that the SHRss are promising and efficient nonviral vectors for siRNA delivery.

Mannose 6‐phosphate‐modified bovine serum albumin nanoparticles for controlled and targeted delivery of sodium ferulate for treatment of hepatic fibrosis

Objectives The aim was to prepare neoglycoprotein‐based nanoparticles for targeted drug delivery to hepatic stellate cells, and to evaluate their characteristics in vitro and in vivo.

Curcumin induces apoptosis in tumor necrosis factor-alpha-treated HaCaT cells

Psoriasis is a benign, chronic skin disease characterized by keratinocyte hyperproliferation and abnormal differentiation. Curcumin, a selective phosphorylase kinase inhibitor, is a natural phytochemical present in turmeric. Curcumin has been confirmed to have anti-inflammatory properties as well as the ability to inhibit proliferation and decrease the expression of pro-inflammatory cytokines in psoriatic keratinocytes. However, the pro-apoptotic effect of curcumin in keratinocytes remains unclear. In the present study, we investigated the effect of curcumin on apoptosis induction in TNF-α-treated HaCaT cells. These results show that curcumin exhibited a significant pro-apoptotic effect on HaCaT cells only in the presence of TNF-α and/or TRAIL. The pro-apoptotic effect of curcumin resulted from the increased expression of TRAIL-R1/R2 and the decreased expression of anti-apoptotic proteins. Our results indicate that both curcumin and TNF-α up-regulated the expression of TRAIL-R1/R2. In addition, the expression of anti-apoptotic proteins (IAP1, IAP2, Bcl-X(L)) was up-regulated by TNF-α but suppressed by curcumin in HaCaT cells. Because these proteins are regulated by NF-κB, we examined the role of curcumin in NF-κB activation. As expected, curcumin inhibited TNF-α-induced activation of NF-κB, including NF-κB-P65. Curcumin also inhibited the TNF-α-induced production of IL-6/IL-8 in HaCaT cells. These results imply that curcumin-induced apoptosis of HaCaT cells only occurs when TNF-α or/and TRAIL are present. Therefore, we believe that curcumin is able to reverse the anti-apoptotic function of TNF-α in HaCaT cells and thus expect curcumin to be successful in the treatment of psoriasis.

Ginsenoside Rb1 and paeoniflorin inhibit transient receptor potential vanilloid-1-activated IL-8 and PGE2 production in a human keratinocyte cell line HaCaT

Ginsenoside Rb1 (GRb1) and paeoniflorin (PF) are active substances of Chinese traditional herbs and have been commonly used to treat skin inflammation diseases, but little is known about the mechanisms involved. In the present study, the effects of GRb1 and PF on the production of inflammatory mediators and the possible mechanisms of transient receptor potential vanilloid-1 (TRPV1) in these mediators induction were explored. It has been shown that GRb1 and PF inhibited the productions of IL-8 and PGE₂ induced by capsaicin (CAP) in HaCaT cells and HEK 293T-TRPV1 cells (which were transgenic and overexpressed TRPV1) but had no effect on HEK 293T mock cells (p<0.05). Besides, CAP was able to induce calcium influx and nuclear factor kappa B(NF-κB) transcriptional activity in HaCaT cells and HEK 293T-TRPV1 cells, but had no effect on HEK 293T mock cells. Furthermore, GRb1 inhibited CAP-induced calcium influx and NF-κB transcriptional activity in both HaCaT cells and HEK 293T-TRPV1 cells. However, PF decreased CAP-induced calcium influx and NF-κB transcriptional activity only in HaCaT cells. This would suggest that GRb1 inhibits CAP-induced calcium influx and NF-κB activity through TRPV1 signal, while calcium influx and NF-κB activity might not be involved in the inhibitory effect of PF on TRPV1 signal. Furthermore, the inhibitory rates of GRb1 and PF on IL-8 and PGE₂ production were higher than those caused by capsazepine, an antagonist of TRPV1, suggesting that GRb1 and PF have great potential in clinical treatment of skin diseases.