Transcutaneous tumor vaccination combined with anti-programmed death-1 monoclonal antibody treatment produces a synergistic antitumor effect.

Transcutaneous immunization (TCI) has the advantages of safety, high efficiency, non-invasiveness and convenient use. The key for a TCI system is transdermal targeted delivery of antigen to dendritic cells (DCs), the most powerful antigen presenting cells. DCs also play an important role in tumor immunotherapy, which provides a huge imagination for the application of TCI to tumor treatment. In this study, a transcutaneous tumor vaccine (TTV) delivery system was developed using the electrospun silk fibroin (SF) and polyvinyl alcohol (PVA) composite nanofibrous patch loaded with mannosylated polyethyleneimine (PEIman)-modified ethosome (Eth) (termed Eth-PEIman). Eth-PEIman showed a good performance in targeting DCs, and the carriers loaded with antigen (encapsulated in Eths) and adjuvant (absorbed in PEIman) were observed effectively induce DCs maturation in vitro. With the tyrosinase-related protein-2 (TRP2) peptide as antigen and oligodeoxynucleotides containing unmethylated CpG motifs as adjuvant, the TTV-loaded patches (TTVP) significantly inhibited the growth of melanoma in a syngeneic mouse model for melanoma by subcutaneous injection of B16F10 cell lines. Moreover, the combined application of the TTVP and anti-programmed death-1 monoclonal antibody (aPD-1) produced a synergistic antitumor effect, which could be related to the infiltration of more CD4+ and CD8+ T cells in the tumor tissues. The application of TTVP also increased the expression of IL-12, which may be part of the mechanism of synergistic antitumor effect between the TTVP and aPD-1. These results suggest that the combination of the TTVP and immune checkpoint blockers could be an effective strategy for tumor treatment. STATEMENT OF SIGNIFICANCE: Transcutaneous immunization has the advantages of safety, high efficiency, non-invasiveness and convenient use. In this study, a novel transcutaneous tumor vaccine patch (TTVP) was developed using tumor antigens-loaded ethosomes that can target dendritic cells percutaneously. Our data demonstrated that the TTVP can significantly inhibit tumor growth. Furthermore, the combination of TTVP and aPD-1 produced a synergistic anti-melanoma effect. Considering its convenience and non-invasiveness, this TTVP system could find good application prospects in immunotherapy. The combination of TTVP and aPD-1 could be a useful strategy for the prevention and treatment of tumors.

Transdermal delivery of interleukin-12 gene targeting dendritic cells enhances the anti-tumour effect of programmed cell death protein 1 monoclonal antibody.

Recent studies have suggested that the anti-tumour effect of the programmed cell death protein 1 monoclonal antibody (aPD-1) depends on the expression of interleukin-12 (IL-12) by dendritic cells (DCs). Since DCs are abundant in skin tissues, transdermal delivery of IL-12 targeting DCs may significantly improve the anti-tumour effect of aPD-1. In this study, a novel mannosylated chitosan (MC)-modified ethosome (Eth-MC) was obtained through electrostatic adsorption. The Eth-MC loaded with plasmid containing the IL-12 gene (pIL-12@Eth-MC) stimulated DCs to express mature-related molecular markers such as CD86, CD80, and major histocompatibility complex-II in a targeted manner. The pIL-12@Eth-MC was then mixed with polyvinyl pyrrolidone solution to make microspheres using the electrospray technique, and sprayed onto the surface of electrospun silk fibroin-polyvinyl alcohol nanofibres to obtain a PVP-pIL-12@Eth-MC/silk fibroin-polyvinyl alcohol composite nanofibrous patch (termed a transcutaneous immunization (TCI) patch). The TCI patch showed a good performance on transdermal drug release. Animal experiments on melanoma-bearing mice showed that topical application of the TCI patches promoted the expression of IL-12 and inhibited the growth of tumour. Furthermore, combined application of the TCI patch and aPD-1 showed a stronger anti-tumour effect than aPD-1 monotherapy. The combination therapy significantly promoted the expression of IL-12, interferon-γ and tumour necrosis factor-α, the infiltration of CD4+ and CD8+ T cells into tumour tissues, and thus promoted the apoptosis of tumour cells. The present study provides a convenient and non-invasive strategy for improving the efficacy of immune checkpoint inhibitor therapy. This study was approved by the Institutional Animal Care and Use Committee at Donghua University (approval No. DHUEC-NSFC-2020-11) on March 31, 2020.

Galactosylated chitosan-modified ethosomes combined with silk fibroin nanofibers is useful in transcutaneous immunization.

Transcutaneous immunization (TCI) has the advantages of avoiding the liver first-pass effect, good compliance and convenient use compared with the traditional oral or injection vaccination. However, the stratum corneum (SC) of the skin is the main obstacle that limits the entry of antigen molecules into the epidermis for activating dendritic cells (DCs). In the present study, the hyaluronic acid (HA) and galactosylated chitosan (GC) modified ethosome (Eth-HA-GC) was prepared through layer-by-layer self-assembly method. Eth-HA-GC has good stability and can be effectively phagocytosed by the bone-marrow-derived DCs (BMDCs) in vitro. The ovalbumin (OVA) loaded Eth-HA-GC (OVA@Eth-HA-GC) can promote BMDCs' expression of CD80, CD86 (DCs maturation-associated marker molecules), TNF-α, IL-2 and IL-6. Subsequently, a novel OVA@Eth-HA-GC-loaded silk fibroin (OVA@Eth-HA-GC/SF) nanofibrous mats were fabricated through green electrospinning. The OVA@Eth-HA-GC/SF mats exhibit good transdermal performance in vitro. Transdermal administration with OVA@Eth-HA-GC/SF mats induced the serum anti-OVA-specific IgG and increased the expression of IFN-γ, IL-2 and IL-6 by spleen cells in vivo. Furthermore, the use of OVA@Eth-HA-GC/SF mats evidently inhibited the growth of EG7 tumor in the murine model. These results demonstrate the OVA@Eth-HA-GC/SF mats can effectively stimulate the immune response to OVA through transdermal administration. In conclusion, the antigens@Eth-HA-GC/SF mats is a promising TCI system.

Polyvinyl Alcohol/Hydroxyethylcellulose Containing Ethosomes as a Scaffold for Transdermal Drug Delivery Applications.

This study aims to develop scaffold for transdermal drug delivery method (TDDM) using electrospinning technique from polyvinyl alcohol (PVA) and hydroxyethylcellulose (HEC). The fluorescein isothiocyanate (FITC) loaded on ethosomes (FITC@Eth) was used as a drug model. The prepared PVA/HEC/FITC@Eth scaffold was characterized via scanning electron microscope (SEM) that show morphology change by adding FITC@Eth. Also, Fourier transform infrared spectroscopy (FTIR), mechanical properties, X-ray diffraction (XRD), thermal gravimetric (TGA) analysis show that the addition of FITC@Eth to PVA/HEC does not change the scaffold properties. Franz diffusion cells were used for in vitro skin permeation experiments using rat dorsal skins. The FITC@Eth penetration was better than that of free FITC due to the presence of ethosome which enhance the potential skin targeting. In conclusion, the prepared PVA/HEC/FITC@Eth scaffold can serve as a promising transdermal scaffold for sustained FITC release.

Polyethylenimine and sodium cholate-modified ethosomes complex as multidrug carriers for the treatment of melanoma through transdermal delivery.

Aim: Multidrug resistance is the main reason for the failure of chemotherapy during the treatment of the tumor. To overcome multidrug resistance, this study attempts to develop a novel transdermal drug-delivery system (TDDS) loading cytotoxic drug and chemosensitizer. Materials & methods: The polyethylenimine-modified ethosomes (Eth-PEI) and sodium cholate-modified ethosomes (Eth-SC) were firstly fabricated, and then a novel TDDS based on the carriers complex of Eth-PEI/Eth-SC was prepared by electrostatic interaction and evaluated both in vitro and in vivo. Results: The Eth-PEI/Eth-SC showed the excellent antitumor effect on treating melanoma, using doxorubicin and curcumin as the cytotoxic drug and chemosensitizer, respectively. Conclusion: The as-prepared TDDS composed of Eth-PEI/Eth-SC loading multidrug is an effective means for treating melanoma.