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Platelet-rich plasma (PRP) is an autologous biologic product used in several fields of medicine for tissue repair due to the regenerative capacity of the biomolecules of its formulation. PRP consists of a plasma with a platelet concentration higher than basal levels but with basal levels of any biomolecules present out of the platelets. Plasma contains extraplatelet biomolecules known to enhance its regenerative properties. Therefore, a PRP containing not only a higher concentration of platelets but also a higher concentration of extraplatelet biomolecules that could have a stronger regenerative performance than a standard PRP. Considering this, the aim of this work is to develop a new method to obtain PRP enriched in both platelet and extraplatelet molecules. The method is based on the absorption of the water of the plasma using hydroxyethyl acrylamide (HEAA)-based hydrogels. A plasma fraction obtained from blood, containing the basal levels of platelets and proteins, was placed in contact with the HEAA hydrogel powder to absorb half the volume of the water. The resulting plasma was characterized, and its bioactivity was analyzed in vitro. The novel PRP (nPRP) showed a platelet concentration and platelet derived growth factor (PDGF) levels similar to the standard PRP (sPRP), but the concentration of the extraplatelet growth factors IGF-1 ( p < 0.0001) and HGF ( p < 0.001) were significantly increased. Additionally, the cells exposed to the nPRP showed increased cell viability than those exposed to a sPRP in human dermal fibroblasts ( p < 0.001) and primary chondrocytes ( p < 0.01). In conclusion, this novel absorption-based method produces a PRP with novel characteristics compared to the standard PRPs, with promising in vitro results that could potentially trigger improved tissue regeneration capacity.

Glucose is an analyte of great importance, both in the clinical and sports fields. Since blood is the gold standard biofluid used for the analytical determination of glucose, there is high interest in finding alternative non-invasive biofluids, such as sweat, for its determination. In this research, we present an alginate-based bead-like biosystem integrated with an enzymatic assay for the determination of glucose in sweat. The system was calibrated and verified in artificial sweat, and a linear calibration range was obtained for glucose of 10-1000 µM. The colorimetric determination was investigated, and the analysis was carried out both in the black and white and in the Red:Green:Blue color code. A limit of detection and quantification of 3.8 µM and 12.7 µM, respectively, were obtained for glucose determination. The biosystem was also applied with real sweat, using a prototype of a microfluidic device platform as a proof of concept. This research demonstrated the potential of alginate hydrogels as scaffolds for the fabrication of biosystems and their possible integration in microfluidic devices. These results are intended to bring awareness of sweat as a complementary tool for standard analytical diagnosis.

Additive manufacturing technology is an emerging method for rapid prototyping, which enables the creation of complex geometries by one-step fabrication processes through a layer-by-layer approach. The simplified fabrication achieved with this methodology opens the way towards a more efficient industrial production, with applications in a great number of fields such as biomedical devices. In biomedicine, blood is the gold-standard biofluid for clinical analysis. However, blood cells generate analytical interferences in many test procedures; hence, it is important to separate plasma from blood cells before analytical testing of blood samples. In this research, a custom-made resin formulation combined with a high-resolution 3D printing methodology were used to achieve a methodology for the fast prototype optimization of an operative plasma separation modular device. Through an iterative process, 17 different prototypes were designed and fabricated with printing times ranging from 5 to 12 min. The final device was evaluated through colorimetric analysis, validating this fabrication approach for the qualitative assessment of plasma separation from whole blood. The 3D printing method used here demonstrates the great contribution that this microfluidic technology will bring to the plasma separation biomedical devices market.

The main problem for the expansion of the use of microfluidic paper-based analytical devices and, thus, their mass production is their inherent lack of fluid flow control due to its uncontrolled fabrication protocols. To address this issue, the first step is the generation of uniform and reliable microfluidic channels. The most common paper microfluidic fabrication method is wax printing, which consists of two parts, printing and heating, where heating is a critical step for the fabrication of reproducible device dimensions. In order to bring paper-based devices to success, it is essential to optimize the fabrication process in order to always get a reproducible device. Therefore, the optimization of the heating process and the analysis of the parameters that could affect the final dimensions of the device, such as its shape, the width of the wax barrier and the internal area of the device, were performed. Moreover, we present a method to predict reproducible devices with controlled working areas in a simple manner.

Fluorescent self assembled monolayers (SAMs) on glass were previouslydeveloped in our group as new sensing materials for metal ions. These fluorescent SAMs arecomprised by fluorophores and small molecules sequentially deposited on a monolayer onglass. The preorganization provided by the surface avoids the need for complex receptordesign, allowing for a combinatorial approach to sensing systems based on small molecules.Now we show the fabrication of an effective microarray for the screening of metal ions andthe properties of the sensing SAMs. A collection of fluorescent sensing SAMs wasgenerated by combinatorial methods and immobilized on the glass surfaces of a custom-made 140 well microtiter-plate. The resulting libraries are easily measured and show variedresponses to a series cations such as Cu 2+ , Co 2+ , Pb 2+ , Ca 2+ and Zn 2+ . These surfaces are notdesigned to complex selectively a unique analyte but rather they are intended to producefingerprint type responses to a range of analytes by less specific interactions. The unselectiveresponses of the library to the presence of different cations generate a characteristic patternfor each analyte, a "finger print" response.