T-cell costimulatory capacity of oral and skin epithelial cells in vitro: presence of suppressive activity in supernatants from skin epithelial cell cultures

Microneedle-Based Delivery: An Overview of Current Applications and Trends

Microneedle arrays (MNA) are considered as one of the most promising resources to achieve systemic effects by transdermal delivery of drugs. They are designed as a minimally invasive, painless system which can bypass the stratum corneum, overcoming the potential drawbacks of subcutaneous injections and other transdermal delivery systems such as chemical enhancers, nano and microparticles, or physical treatments. As a trendy field in pharmaceutical and biomedical research, its applications are constantly evolving, even though they are based on very well-established techniques. The number of molecules administered by MNA are also increasing, with insulin and vaccines administration being the most investigated. Furthermore, MNA are being used to deliver cells and applied in other organs and tissues like the eyes and buccal mucosae. This review intends to offer a general overview of the current state of MNA research, focusing on the strategies, applications, and types of molecules delivered recently by these systems. In addition, some information about the materials and manufacturing processes is presented and safety data is discussed.

Microneedle-Mediated Vaccine Delivery to the Oral Mucosa

The oral mucosa is a minimally invasive and immunologically rich site that is underutilized for vaccination due to physiological and immunological barriers. To develop effective oral mucosal vaccines, key questions regarding vaccine residence time, uptake, adjuvant formulation, dose, and delivery location must be answered. However, currently available dosage forms are insufficient to address all these questions. An ideal oral mucosal vaccine delivery system would improve both residence time and epithelial permeation while enabling efficient delivery of physicochemically diverse vaccine formulations. Microneedles have demonstrated these capabilities for dermal vaccine delivery. Additionally, microneedles enable precise control over delivery properties like depth, uniformity, and dosing, making them an ideal tool to study oral mucosal vaccination. Select studies have demonstrated the feasibility of microneedle-mediated oral mucosal vaccination, but they have only begun to explore the broad functionality of microneedles. This review describes the physiological and immunological challenges related to oral mucosal vaccine delivery and provides specific examples of how microneedles can be used to address these challenges. It summarizes and compares the few existing oral mucosal microneedle vaccine studies and offers a perspective for the future of the field.

A New Rat Model of Maxilla Allotransplantation

We developed a rat model to test the effects of vascularized maxilla allotransplantation on composite maxillary substructures. Allograft maxilla transplantations were performed across the major histocompatibility barrier between 10 Lewis-Brown-Norway (RT1(n+l)) and 10 Lewis (RT1(l)) recipient rats under cyclosporin A monotherapy. Grafts were dissected along Le-Fort II osteotomy lines based on the common carotid artery and external jugular vein and transplanted to the anterior abdominal wall via microvascular anastomosis. Allografts were examined by tomography, flow cytometry, angiography, and histology. Three of the allografts survived up to 105 days without any signs of rejection. High level of donor-specific chimerism for T-cell and B-cell lineages was maintained in the peripheral blood. The incisors continued to grow; teeth buds, bone, cartilage, and mucosa remained intact. Moderate inflammation of the nasal, oral mucosa, and keratinous metaplasia was noted histologically. We created a maxilla allotransplantation model that allows the study of immunologic responses and demonstrates potential clinical applications based on the growth properties of the allograft.

The innate immune system is activated by stimulation of vaginal epithelial cells with Staphylococcus aureus and toxic shock syndrome toxin 1

Despite knowledge of the effects of toxic shock syndrome (TSS) toxin 1 (TSST-1) on the adaptive immune system, little is known about stimulation of the innate immune system, particularly epithelial cells. This study investigated the interactions of TSS Staphylococcus aureus and TSST-1 with human vaginal epithelial cells (HVECs) and porcine mucosal surfaces. When cocultured with HVECs for 6 h, TSS S. aureus MN8 proliferated, formed aggregates on the HVEC surfaces, and produced exotoxins. Receptor binding studies showed that 35S-TSST-1 bound to 5 x 10(4) receptors per HVEC, with saturation at 15 min. Affymetrix Human GeneChip U133A microarray analysis determined S. aureus MNSM (100 bacteria/HVEC) caused at least twofold up- or down-regulation of 410 HVEC genes by 6 h; these data were also confirmed with S. aureus MN8. TSST-1 (100 microg/ml) caused up- or down-regulation of 2,386 HVEC genes by 6 h. In response to S. aureus, the HVEC genes most up-regulated compared to those in controls were those coding for chemokines or cytokines--MIP-3alpha, 478-fold; GRO-alpha, 26-fold; GRO-beta, 14-fold; and GRO-gamma, 30-fold--suggesting activation of innate immunity. TSST-1 also caused up-regulation of chemokine/cytokine genes. Chemokine/cytokine gene up-regulation was confirmed by enzyme-linked immunosorbent assays measuring the corresponding proteins induced by S. aureus and TSST-1. S. aureus MN8, when incubated with porcine vaginal tissue, increased the flux of 35S-TSST-1 across the mucosal surface. This was accompanied by influx of lymphocytes into the upper layers of the tissue. These data suggest innate immune system activation through epithelial cells, reflected in chemokine/cytokine production and influx of lymphocytes, may cause changes in vaginal mucosa permeability, facilitating TSST-1 penetration.