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Borate Phosphor for Phototherapy Application
Published in S. K. Omanwar, R. P. Sonekar, N. S. Bajaj, Borate Phosphors, 2022
The ability of UVR to affect the skin's immune system was first recognized in the early 1970s. It is now accepted that UVA, UVB and PUVA therapy exert a variety of immunomodulatory effects on human skin, and that this is of critical importance for the therapeutic efficacy of phototherapy. The actual therapeutic relevance of these effects is mainly determined by the depth of penetration of the type of UV radiation employed. Figure 5.4 shows the skin penetration of UV radiations. Most of the UVC rays are absorbed by the ozone layer and therefore they do not reach to the earth's surface. However, UVA and UVB rays pass through the ozone layer and come at the earth surface. UVB mainly affects epidermal keratinocytes and Langerhans cells, whereas UVA penetrates more deeply into the dermis, thereby affecting dermal fibroblasts, dermal dendritic cells, endothelial cells and skin – infiltrating inflammatory cells such as T lymphocytes, mast cells and granulocytes. Many of these effects have been identified using animal models or through in vitro studies employing cultured human skin cells [24].
Paediatrics
Published in David A Lisle, Imaging for Students, 2012
Langerhans cell histiocytosis (LCH) describes a spectrum of disorders, the common feature being histiocytic infiltration of tissues and aggressive bone lesions. LCH may be subclassified as restricted or extensive LDH. Extensive LDH refers to visceral organ involvement with or without bone lesions. Visceral involvement may produce organ dysfunction and failure. Skin rash and diabetes insipidus are common. Restricted LCH refers to monostotic bone or polyostotic bone lesions, or isolated skin lesions. The monostotic bone lesion of LCH occurs in children with a peak age of incidence of five to ten years, though may also be seen in older patients. Clinical presentation may be with local pain or pathological fracture (see Fig. 8.9). Radiographically, LCH produces focal well-defined lytic skeletal lesions in the skull, spine and long bones.
Role of Dendrimers in the Development of New Dendritic Cells Immunotherapies Against HIV-1 Infection
Published in Anne-Marie Caminade, Cédric-Olivier Turrin, Jean-Pierre Majoral, Phosphorus Dendrimers in Biology and Nanomedicine, 2018
Rosa Reguera, Joao Rodrigues, Jose Correa, M. Angeles Munoz-Fernandez
The application of nanotechnology for prevention and/or treatment of HIV-1 infection has already been a reality [43–50]. Applications of nanotechnology platforms enhance the current treatments and can be used as novel therapeutic agents in anti- HIV immunotherapy and gene therapy. Various nanosystems have been researched for ex vivo and in vivo targeting of DCs and for delivery of small molecules, proteins, and DNA showing potential for immunotherapy [47,50–52]. These nanosystems release antigens in a controlled manner and effectively target DCs [44,51,52]. These nanosystems use different ways such as encapsulating antigens in their core or absorbing these small molecules on their functionalized surface with the purpose to deliver them. For instance, poly(ethylene glycol) (PEG), stabilized poly(propylene sulfide), polymer nanoparticles [53], cross-linked polymer nanoparticles with a pH-responsive core, and hydrophilic charged shell [54] or nanoparticles of the copolymer poly(d,l-lacticide-co- glycolide) (PLGA) [55] have been used to deliver antigens such as proteins to DCs. Other studies using HIV-1 gp160 or gp41 proteins encapsulated in liposomes [56,57] or p24 protein adsorbed on the surface of anionic poly(d,l-lactide) (PLA) nanoparticles induced antigen-specific cellular immunity when targeted to DCs in a mice model [58,59]. Nevertheless, nanoparticles have potential not only as carriers in immunotherapies but also as adjuvants in vaccine development [60]. One of the most advanced clinical applications of nanocompounds for HIV-1 immunotherapy is the DermaVir patch [61,62]. This nanoparticle is based on poly(ethyleneimine) (PEI) mannose (PEIm), glucose and HIV-1 antigen coding DNA plasmid and delivered to epidermis. Antigens captured by Langerhans cells in the epidermis DCs mature and present the antigens to T cells, promoting an increased cellular immune response. DermaVir administered in skin path is in phase II clinical trial.
Conceptualisation of a novel electromechanical system for small-volume needle-free jet injection
Published in Engineering Applications of Computational Fluid Mechanics, 2023
Needle-free jet injection systems (NFJIS) use the momentum possessed by a high-velocity microjet to penetrate the skin barrier. Most commercially available needle-free jet injectors can deliver drugs of 100 μL into the intradermal or subcutaneous compartments of the skin tissue. The NFJIS can also be used for the delivery of vaccines, insulin, and anesthesia (Weniger & Papania, 2013). However, these systems are reported to cause occasional bruising, bleeding, and soreness. Moreover, no significant difference is noted in the pain experienced with the NFJIS and that of a traditional needle injection system (Gozdemir et al., 2016; Tagawa et al., 2013). It has been hypothesised that pain associated with the injection is due to the large-volume of a single dose of drug administration, and several studies have rationalised that the pain can be reduced by decreasing the penetration depth and injection volume (Arora et al., 2007; Römgens et al., 2016). Also, injections into the superficial skin layers like epidermis and dermis possess many advantages over injections into subcutaneous and muscle layers. For example, Langerhans cells in the epidermis are dendritic cells, responsible for the first stage of an immune response and vaccine delivery to the epidermis can reduce the required dose by a factor of five (Schoppink & Rivas, 2022). This motivated new investigations to limit the penetration depth of an NFJIS by controlling the injection volume.
Genetic variants affecting chemical mediated skin immunotoxicity
Published in Journal of Toxicology and Environmental Health, Part B, 2022
Isisdoris Rodrigues de Souza, Patrícia Savio de Araujo-Souza, Daniela Morais Leme
Langerhans cells (LC) are professional APCs of the epidermis that migrate to lymph nodes and stimulate T lymphocyte responses (Clayton et al. 2017; Quaresma 2019). As a dendritic cell (DC), LC might capture, process, and present antigens to naïve T cells (Klechevsky 2015). During skin sensitization, LC mobilization towards the regional lymph nodes and concomitant maturation (to DCs) are induced and regulated by cutaneous cytokines. Thus, LC process and present the captured antigen on their surface associated with MHC molecules. This complex may be subsequently recognized by naïve T cells, thus instigating clonal expansion of antigen‐specific T lymphocytes and enabling development of cellular immunological memory (Divkovic et al. 2005).