Optimization of Novel Mucoadhesive In Situ Film Forming Periodontal Drug Delivery System for Chemotherapeutic Agents

Introduction

The objective of the present investigation was to develop and evaluate mucoadhesive in situ film forming periodontal drug delivery system (MIFPDDS) for local delivery of chemotherapeutic agents. Ethyl cellulose, a film forming release retardant, was used in combination with Eudragit RL100, a mucoadhesive polymer, and polyvinylpyrrolidone K-30 to develop MIFPDDS.

Materials and methods

A simplex lattice design was employed to achieve an optimum solvent blend (N-methyl-2-pyrrolidone, polyethylene glycol-200, and propylene glycol) which has rapid film formation capacity and low viscosity. The prepared MIFPDDS was evaluated for various parameters such as in vitro film forming capacity, viscosity, in vitro diffusion study, ex vivo mucoadhesion study, stability study, and compatibility. A 32 full-factorial design was used to investigate the influence of formulation variables.

Results and discussion

Drug release data from all formulations were fitted to different kinetic models, and the Korsmeyer–Peppas model was found the best fit model. Increasing the concentration of each polymeric component increases viscosity, and time for 50, 70, and 90 % drug release was observed and graphically represented by the surface response and contour plots. The formulation of batches MIF1—PCM4, MIF6, and MIF7 failed to give the desired results for the first hour drug release and MIF8 and MIF9 failed to show viscosity below 70 cPs.

Conclusion

The formulation of batch MIF5 containing 3 % (w/v) of ethyl cellulose and 8 % (w/v) of Eudragit RL100 was considered as optimum formulation.     

NCoR1 fine-tunes type-I IFN response in cDC1 dendritic cells by directly regulating Myd88-IRF7 axis under TLR9

Plasmacytoid dendritic cells (DCs) are reported to induce robust type-I interferon (IFN) response, whereas cDC1 DCs develop moderate type-I IFN response upon TLR9 stimulation. It is very interesting to understand how this signaling under TLR9 is tightly regulated for the induction of type-I IFNs. Here, we report co-repressor protein NCoR1 as the major factor fine-tuning the signaling pathways regulating IFN-β expression under TLR9 in cDC1 DCs. We found that NCoR1 knockdown induced a robust IFN-β-mediated antiviral response upon TLR9 activation in cDC1 DCs. At the molecular level, we showed that NCoR1 directly repressed MyD88-IRF7 signaling axis in cDC1 cells. Therefore, NCoR1 depletion enhanced pIRF7 levels, IFN-β secretion, and downstream pSTAT1-pSTAT2 signaling, leading to sustained induction of IFN stimulatory genes. Integrative genomic analysis depicted strong enrichment of an antiviral gene-module in CpG-activated NCoR1 knockdown DCs upon TLR9 activation. Moreover, we confirmed our findings in primary DCs derived from splenocytes of WT and NCoR1 DC^−/− animals, which showed protection from Sendai and Vesicular Stomatitis viruses upon CpG activation. Ultimately, we identified that NCoR1–HDAC3 complex is involved in repressing the type-I IFN response in cDC1 DCs.     

Discordant and heterogeneous clinically relevant genomic alterations in circulating tumor cells vs plasma DNA from men with metastatic castration resistant prostate cancer

Circulating tumor cell (CTC) and cell‐free (cf) DNA‐based genomic alterations are increasingly being used for clinical decision‐making in oncology. However, the concordance and discordance between paired CTC and cfDNA genomic profiles remain largely unknown. We performed comparative genomic hybridization (CGH) on CTCs and cfDNA, and low‐pass whole genome sequencing (lpWGS) on cfDNA to characterize genomic alterations (CNA) and tumor content in two independent prospective studies of 93 men with mCRPC treated with enzalutamide/abiraterone, or radium‐223. Comprehensive analysis of 69 patient CTCs and 72 cfDNA samples from 93 men with mCRPC, including 64 paired samples, identified common concordant gains in FOXA1, AR, and MYC, and losses in BRCA1, PTEN, and RB1 between CTCs and cfDNA. Concordant PTEN loss and discordant BRCA2 gain were associated with significantly worse outcomes in Epic AR‐V7 negative men with mCRPC treated with abiraterone/enzalutamide. We identified and externally validated CTC‐specific genomic alternations that were discordant in paired cfDNA, even in samples with high tumor content. These CTC/cfDNA‐discordant regions included key genomic regulators of lineage plasticity, osteomimicry, and cellular differentiation, including MYCN gain in CTCs (31%) that was rarely detected in cfDNA. CTC MYCN gain was associated with poor clinical outcomes in AR‐V7 negative men and small cell transformation. In conclusion, we demonstrated concordance of multiple genomic alterations across CTC and cfDNA platforms; however, some genomic alterations displayed substantial discordance between CTC DNA and cfDNA despite the use of identical copy number analysis methods, suggesting tumor heterogeneity and divergent evolution associated with poor clinical outcomes.