Development of paclitaxel loaded pegylated gelatin targeted nanoparticles for improved treatment efficacy in non-small cell lung cancer (NSCLC): an in vitro and in vivo evaluation study.

PURPOSE: To develop and evaluate paclitaxel (PTX) loaded pegylated gelatin targeted nanoparticles for improved efficacy in non-small cell lung cancer (NSCLC) treatment. METHOD: PTX loaded gelatin nanoparticles (PTX-GNP) were prepared by crosslinking with glutaraldehyde aqueous solution. These nanoparticles (NPs) were further incubated with PEG 400 to form PEGylated NPs (PEG-PTX-GNP). The NPs were evaluated for surface morphology, size, zeta potential, encapsulation efficiency, drug loading, in vitro drug release, cytotoxicity in an assay on cancer cell lines L132, in vitro cellular uptake in an assay in L132 and 293T cell lines, in vivo antitumor activity on female Balb/c mice, pulmonary deposition, histopathology, and immunohistochemical properties. RESULTS: The nanoparticles were of spherical shape with smooth surface characteristics. The observed DL was of 20.18 to 32.11%, as particle size was of 90 to 115 nm. Zeta potential and polydispersity index (PDI) were within acceptable ranges. Encapsulation was effective when the NPs had a size of 80.50 nm to 98.12 nm. The PEGylated PTX loaded nanoparticles (PEG-PTX-GNP, GNP4) showed similar PTX release profile to that of the NP4 formulation. PEGylated NPs showed the desired PTX release pattern that is required for cancer treatment. In an in vitro cytotoxicity study, PEG-PTX-GNP showed the maximum antiproliferative activity over the period of 24 hours, followed by PTX-GNP, pure PTX and BPEG-GNP. PEG-PTX-GNP showed the highest internalization within both cell lines, followed by PTX-GNP and pure PTX. The survival rate of animals in PEG-PTX-GNP group was 100%, proving the safety and efficacy of the treatment. PEG-PTX-GNP showed the highest antitumor activity as compared to other formulations. The pulmonary deposition rate was the highest (6.5 to 12.55 µg/g) in PEG-PTX-GNP formulations. Histopathology and immunohistochemical study proved that PEG-PTX-GNP had greater anticancer potential than other tested formulations. CONCLUSION: This study confirms the potential use of paclitaxel loaded PEGylated gelatin targeted nanoparticles for improved efficacy in non-small cell lung cancer (NSCLC) treatment.

HLA-DR expression on regulatory T cells is closely associated with the global immune activation in HIV-1 infected subjects naïve to antiretroviral therapy.

BACKGROUND: The frequencies of regulatory T cells (Tregs) increased over the HIV infection but its counts actually decreased. We proposed that the decrease of Treg counts may cause the reduction of inhibitory effect and thereby account for the over-activation of Tregs during HIV infection. However, it remains unknown whether Tregs are also over-activated and thereafter the activation induced death may lead to the decrease of Tregs. METHODS: Tregs were defined as CD4(+)CD25(+)CD127(lo/-) T cells. Eighty-one HIV-1 infected patients were enrolled in our study, and twenty-two HIV-1 seronegative donors were recruited as the control. The levels of HLA-DR on Tregs were determined by FACSAria flow cytometer. RESULTS: Compared to HIV-1 seronegative donors, the levels of HLA-DR on CD4(+)CD25(+)CD127(lo/-) Tregs were significantly increased in HIV-1 infected patients, and its increase was positively associated with viral loads (r = 0.3163, P = 0.004) and negatively with CD4 T-cell counts (r = -0.4153, P < 0.0001). In addition, significant associations between HLA-DR expression on CD4(+)CD25(+)CD127(lo/-) Tregs and the percentages of HLA-DR, CD38, Ki67 expressing CD4(+) and CD8(+) T cells were also identified. CONCLUSION: HLA-DR on Tregs is a good marker for viral replication and disease progression. The over-activation of Tregs might result in the decrease of Tregs.