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Microneedlepatches, also called microarray patches(MAP),are an emergingtechnology for deliveryand samplingof drugs, vaccines and other materials. This review focuses on the materials ...and methods used to fabricate dissolvable microneedles(DMN)for pharmaceutical use.We outlinethe relative use ofexcipients, active pharmaceutical ingredients (API) and methods usedfor DMN fabrication. An extensive search of primary literature, up to April 2021,identified 328 papers under the key terms “dissolvable microneedles” or “polymeric microneedles”.We based the classification of materials on pharmacopoeia definitions.The majority (76%) ofthe identifiedpublications examined licensed or model therapeutic small molecule drugs. Mostreports (58%)focused ondrugs or vaccinesthat are licensed for clinical use. Therelativeuse of excipientswith drug-containing compared to vaccine-containing DMN is discussed.Tenpolymers and sugarswereused for both drug and vaccine DMN.Themost frequentmethods to produce DMNwerecasting into moulds using centrifugationorvacuum filling. Novel methods reported include centrifugal lithography and 3D printing. This review provides insight intomaterialselection,thefeasibilityofproductionmethodsat industrial scaleand outlines considerations for novel DMN patch fabrication.
Dissolvable microneedle (DMN) patches for immunization have multiple benefits, including vaccine stability and ease-of-use. However, conventional DMN fabrication methods have several drawbacks. Here ...we describe a novel, microfluidic, drop dispensing-based dissolvable microneedle production method that overcomes these issues. Uniquely, heterogeneous arrays, consisting of microneedles of diverse composition, can be easily produced on the same patch. Robustness of the process was demonstrated by incorporating and stabilizing adenovirus and MVA vaccines. Clinically-available trivalent inactivated influenza vaccine (TIV) in DMN patches is fully stable for greater than 6months at 40°C. Immunization using low dose TIV-loaded DMN patches induced significantly higher antibody responses compared to intramuscular-based immunization in mice. TIV-loaded patches also induced a broader, heterosubtypic neutralizing antibody response. By addressing issues that will be faced in large-scale fill-finish DMN fabrication processes and demonstrating superior thermostable characteristics and immunogenicity, this study progresses the translation of this microneedle platform to eventual clinical deployment.
Precisely dispensing formulation onto microneedle moulds permits the production of heterogeneous patches without wasted material. Influenza vaccine-loaded microneedle patches induce broader neutralizing antibody responses compared to intramuscular injection. Display omitted
Nonsyndromic cleft lip with/without cleft palate (nsCL/P) and nonsyndromic cleft palate only (nsCPO) are the most frequent subphenotypes of orofacial clefts. A common syndromic form of orofacial ...clefting is Van der Woude syndrome (VWS) where individuals have CL/P or CPO, often but not always associated with lower lip pits. Recently, ∼5% of VWS-affected individuals were identified with mutations in the grainy head-like 3 gene (GRHL3). To investigate GRHL3 in nonsyndromic clefting, we sequenced its coding region in 576 Europeans with nsCL/P and 96 with nsCPO. Most strikingly, nsCPO-affected individuals had a higher minor allele frequency for rs41268753 (0.099) than control subjects (0.049; p = 1.24 × 10−2). This association was replicated in nsCPO/control cohorts from Latvia, Yemen, and the UK (pcombined = 2.63 × 10−5; ORallelic = 2.46 95% CI 1.6–3.7) and reached genome-wide significance in combination with imputed data from a GWAS in nsCPO triads (p = 2.73 × 10−9). Notably, rs41268753 is not associated with nsCL/P (p = 0.45). rs41268753 encodes the highly conserved p.Thr454Met (c.1361C>T) (GERP = 5.3), which prediction programs denote as deleterious, has a CADD score of 29.6, and increases protein binding capacity in silico. Sequencing also revealed four novel truncating GRHL3 mutations including two that were de novo in four families, where all nine individuals harboring mutations had nsCPO. This is important for genetic counseling: given that VWS is rare compared to nsCPO, our data suggest that dominant GRHL3 mutations are more likely to cause nonsyndromic than syndromic CPO. Thus, with rare dominant mutations and a common risk variant in the coding region, we have identified an important contribution for GRHL3 in nsCPO.
Fingolimod has generally shown neuroprotective effects in stroke models. Here, we tested the hypothesis that fingolimod modulates T-cell cytokine production towards a regulatory phenotype. Second, we ...investigated how fingolimod altered the Treg suppressive function and the sensitivity of effector T cells to regulation. Mice that had underwent the permanent electrocoagulation of the left middle cerebral artery received saline or fingolimod (0.5 mg/kg) daily for 10-days post-ischaemia. Fingolimod improved neurobehavioural recovery compared to saline control and increased Treg frequency in the periphery and brain. Tregs from fingolimod-treated animals had a higher expression of CCR8. Fingolimod increased the frequencies of CD4
IL-10
, CD4
IFN-γ
and CD4
IL-10
IFN-γ
cells in spleen and blood, and CD4
IL-17
cells in the spleen, with only minor effects on CD8
T-cell cytokine production. Treg from post-ischaemic mice had reduced suppressive function compared to Treg from non-ischaemic mice. Fingolimod treatment rescued this function against saline-treated but not fingolimod-treated CD4
effector T cells. In conclusion, fingolimod seems to improve the suppressive function of Treg post-stroke while also increasing the resistance of CD4
effector cells to this suppression. Fingolimod's capacity to increase both effector and regulatory functions may explain the lack of consistent improvement in functional recovery in experimental brain ischaemia.
The role of immunity in all stages of stroke is increasingly being recognized, from the pathogenesis of risk factors to tissue repair, leading to the investigation of a range of immunomodulatory ...therapies. In the acute phase of stroke, proposed therapies include drugs targeting pro-inflammatory cytokines, matrix metalloproteinases, and leukocyte infiltration, with a key objective to reduce initial brain cell toxicity. Systemically, the early stages of stroke are also characterized by stroke-induced immunosuppression, where downregulation of host defences predisposes patients to infection. Therefore, strategies to modulate innate immunity post-stroke have garnered greater attention. A complementary objective is to reduce longer-term sequelae by focusing on adaptive immunity. Following stroke onset, the integrity of the blood-brain barrier is compromised, exposing central nervous system (CNS) antigens to systemic adaptive immune recognition, potentially inducing autoimmunity. Some pre-clinical efforts have been made to tolerize the immune system to CNS antigens pre-stroke. Separately, immune cell populations that exhibit a regulatory phenotype (T- and B- regulatory cells) have been shown to ameliorate post-stroke inflammation and contribute to tissue repair. Cell-based therapies, established in oncology and transplantation, could become a strategy to treat the acute and chronic stages of stroke. Furthermore, a role for the gut microbiota in ischaemic injury has received attention. Finally, the immune system may play a role in remote ischaemic preconditioning-mediated neuroprotection against stroke. The development of stroke therapies involving organs distant to the infarct site, therefore, should not be overlooked. This review will discuss the immune mechanisms of various therapeutic strategies, surveying published data and discussing more theoretical mechanisms of action that have yet to be exploited.
Although the HPV vaccine is highly safe and effective, its uptake is sub-optimal in many countries, including Ireland. There is therefore a need to identify appropriate interventions that will ...increase HPV vaccine acceptance by parents. In this study, we took a systematic approach to understand the factors that influence HPV vaccine uptake by parents of adolescent girls in Ireland to define suitable behaviour change interventions that would support positive vaccine decision-making in the future. Specifically, we conducted semi-structured interviews, used a Theoretical Domains Framework (TDF)-based topic guide, to gain insight into the knowledge, beliefs, attitudes and current behaviours of parents with respect to their HPV vaccine decision. Transcripts were analysed using the TDF. The Behaviour Change Wheel (BCW) was used to identify relevant intervention functions and the Behaviour Change Technique Taxonomy version 1 (BCTTv1), to identify relevant intervention techniques. All parents discussed the essential role of healthcare providers in vaccine decision-making. Complacency and confidence were important factors in decision-making by vaccine hesitant parents. Five BCW intervention functions were identified as appropriate, namely; education; persuasion; environmental restructuring; modelling and enablement. To our knowledge, this is the first study to systematically evaluate HPV vaccine decision-making using behaviour change theory and identify suitable intervention strategies to promote positive vaccine decision-making using this approach.
Vaccine hesitancy is a complex, context-specific issue that negatively impacts vaccine uptake. During the COVID-19 pandemic, vaccine mis- and dis-information on social media negatively impacted on ...COVID-19 vaccine acceptance. University students' beliefs and behaviors surrounding vaccine decision-making is less studied, but this population is important in disease transmission, vaccine uptake and effectiveness. Here, we surveyed students in a third-level Irish university, in September 2022, when pandemic restrictions had been removed, to primarily determine if their use of, and influence by, mainstream and social media correlated with their willingness to receive a COVID-19 vaccine or any vaccine. We analyzed 151 responses and found no significant correlation between students' willingness to receive either a COVID-19 vaccine or any vaccine and their use of social media. There were significant links between vaccine acceptance and a range of factors, namely accommodation type, social media behaviors, perceived exposure to vaccine mis- or dis-information and previous vaccine uptake. This study provides a preliminary insight into drivers of university student COVID-19 and general vaccine willingness. It provides initial data, in the context of post-pandemic restrictions, to support further development of interventions to enhance vaccine uptake in third-level students in Ireland.
Microneedles (MNs) are designed to specifically target the outermost, skin barrier layer, the stratum corneum, creating transient pathways for minimally invasive transcutaneous delivery. It is ...reported that MNs can facilitate delivery without stimulating the pain receptors or damaging blood vessels that lie beneath, thus being perceived as painless and associated with reduced bleeding. This immunocompetence of the skin, coupled with its ease of access, makes this organ an attractive vaccination site. The purpose of this review was to collate primary scientific literature pertaining to MN-mediated in vivo vaccination programmes. A total of 62 original research articles are presented, compiling vaccination strategies in 6 different models (mouse, rat, guinea pig, rabbit, pig, macaque and human). Vaccines tested span a wide range of viral, bacterial and protozoan pathogens and includes 7 of the 13 vaccine-preventable diseases, as defined by the WHO. This review highlights the paucity of available clinical trial data. MN-delivered vaccines have demonstrated safety and immunogenicity in pre-clinical models and boast desirable attributes such as painless administration, thermostability, dose-sparing capacity and the potential for self-administration. These advantages should contribute to enhanced global vaccine access.
The cessation of the oral poliovirus vaccine (OPV) and the inclusion of inactivated poliovirus (IPV) into all routine immunization programmes, strengthens the need for new IPV options. Several novel ...delivery technologies are being assessed that permit simple yet efficacious and potentially dose-sparing administration of IPV. Current disadvantages of conventional liquid IPV include the dependence on cold chain and the need for injection, resulting in high costs, production of hazardous sharps waste and requiring sufficiently trained personnel. In the current study, a dissolvable microneedle (DMN) patch for skin administration that incorporates trivalent inactivated Sabin poliovirus vaccine (sIPV) was developed. Microneedles were physically stable in the ambient environment for at least 30 min and efficiently penetrated skin. Polio-specific IgG antibodies that were able to neutralize the virus were induced in rats upon administration using trivalent sIPV-containing microneedle patches. These sIPV-patch-induced neutralizing antibody responses were comparable to higher vaccine doses delivered intramuscularly for type 1 and type 3 poliovirus serotypes. Moreover, applying the patches to the flank elicited a significantly higher antibody response compared to their administration to the ear. This study progresses the development of a skin patch-based technology that would simplify vaccine administration of Sabin IPV and thereby overcome logistic issues currently constraining poliovirus eradication campaigns.
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•Trivalent Sabin poliovirus vaccine (sIPV) was incorporated into dissolvable microneedle (DMN) patches for skin administration.•Microneedles were physically stable in the ambient environment for at least 30 min and efficiently penetrated skin.•Patch-mediated administration of sIPV induced neutralizing antibodies comparable to higher vaccine delivered intramuscularly•Applying patches to the flank elicited significantly higher antibody responses compared to administration to the ear.
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