Manufacture Techniques of Chitosan-Based Microcapsules to Enhance Functional Properties of Textiles

In recent years, the textile industry has been moving to novel concepts of products, which could deliver to the user, improved performances. Such smart textiles have been proven to have the potential to integrate within a commodity garment advanced feature and functional properties of different kinds. Among those functionalities, considerable interest has been played in functionalizing commodity garments in order to make them positively interact with the human body and therefore being beneficial to the user health. This kind of functionalization generally exploits biopolymers, a class of materials that possess peculiar properties such as biocompatibility and biodegradability that make them suitable for bio-functional textile production. In the context of biopolymer chitosan has been proved to be an excellent potential candidate for this kind of application given its abundant availability and its chemical properties that it positively interacts with biological tissue. Notwithstanding the high potential of chitosan-based technologies in the textile sectors, several issues limit the large-scale production of such innovative garments. In facts the morphologies of chitosan structures should be optimized in order to make them better exploit the biological activity; moreover a suitable process for the application of chitosan structures to the textile must be designed. The application process should indeed not only allow an effective and durable fixation of chitosan to textile but also comply with environmental rules concerning pollution emission and utilization of harmful substances. This chapter reviews the use of microencapsulation technique as an approach to effectively apply chitosan to the textile material while overcoming the significant limitations of finishing processes. The assembly of chitosan macromolecules into microcapsules was proved to boost the biological properties of the polymer thanks to a considerable increase in the surface area available for interactions with the living tissues. Moreover, the incorporation of different active substances into chitosan shells allows the design of multifunctional materials that effectively combine core and shell properties. Based on the kind of substances to be incorporated, several encapsulation processes have been developed. The literature evidences how the proper choices concerning encapsulation technology, chemical formulations, and process parameter allow tuning the properties and the performances of the obtained microcapsules. Furthermore, the microcapsules based finishing process have been reviewed evidencing how the microcapsules morphology can positively interact with textile substrate allowing an improvement in the durability of the treatment. The application of the chitosan shelled microcapsules was proved to be capable of imparting different functionalities to textile substrates opening possibilities for a new generation of garments with improved performances and with the potential of protecting the user from multiple harms. Lastly, a continuous interest was observed in improving the process and formulation design in order to avoid the usage of toxic substances, therefore, complying with an environmentally friendly approach

Screening for HIV, hepatitis B and syphilis on dried blood spots: A promising method to better reach hidden high-risk populations with self-collected sampling

Many people at high risk for sexually transmitted infections (STIs), e.g., men who have sex with men (MSM), are not optimally reached by current sexual health care systems with testing. To facilitate testing by home-based sampling or sampling in outreach setting we evaluated dried blood spots (DBS), a method for self-collected blood sampling for serological screening of HIV, hepatitis B (HBV) and syphilis. The aims of this study were to assess the acceptability and feasibility of self-collected DBS and to compare the test results for screening of HIV, HBV and syphilis from DBS with blood drawn by venous puncture.DBS were collected from men who have sex with men (MSM), visiting the STI clinic of the public health service South Limburg (n = 183) and HIV positive and HBV positive patients (n = 34), visiting the outpatient clinics of the Maastricht University Medical Centre in the period January 2012-April 2015. The 93 first participating MSM visiting the STI clinic were asked to fill in a questionnaire about the feasibility and acceptability about self-collection of DBS in a setting without going to a health care facility and were asked to collect the DBS themselves. Serological screening tests for HIV (HIV combi PT, Roche), HBV (HBsAg, Roche) and syphilis (Treponema pallidum Ig, Biokit 3.0) were performed on DBS and on blood drawn by venous puncture, which was routinely taken for screening.In total 217 participants were included in the study with a median age of 40 years (range between 17-80). Of MSM 84% agreed that it was clear and easy to do the finger-prick, while 53% agreed that it was clear and easy to apply the blood onto the DBS card. Also, 80% of MSM would use the bloodspot test again. In 91% (198) of DBS, sufficient material was collected to perform the three tests. No difference was observed in DBS quality between self-collected DBS and health care worker collected DBS. For HIV (n = 195 DBS-serum pairs) sensitivity and specificity were 100%. For HBV the sensitivity for HBsAg (n = 202) was 90% and specificity was 99%. For syphilis (n = 191) the sensitivity of the DBS was 93% with a specificity of 99%. Analysis of the DBS of HIV positive participants (n = 38) did show similar test performance for HBV and syphilis as in HIV negatives.DBS is an acceptable self-sampling method for MSM, as there was no difference in DBS quality in self-collected and health care worker collected DBS. Test performance, i.e., its high sensitivity (>90%) and specificity (>99%) measures show that DBS is a valid alternative for venous blood puncture. Especially when DBS is combined with home-collected sampling for Chlamydia trachomatis and Neisseria gonorrhoeae, complete STI screening can be done in outreach setting and/or home-collected sampling in MSM