Interactions of Cardiac Proteins with Plasma-Synthesized Polypyrrole (PSPy) to Improve Adult Cardiomyocytes Culture.

Plasma-Synthesized Polypyrrole (PSPy) has been reported as a biomaterial suitable for cell growth in vitro and in vivo. An experimental duplicate was carried out that showed the growth of cardiomyocytes with PSPy, following a protocol previously reported by the working group. The cardiomyocytes cultured with the biomaterial retained their native morphological characteristics, a fundamental key to improving cardiac cell therapy procedures. Such observations motivated us to investigate the molecular characteristics of the biomaterial and the type of interactions that could be occurring (mainly electrostatic, hydrogen bonds, and non-polar). Additionally, PSPy has been studied to establish the probable mechanisms of action of the biomaterial, in particular, its action on a group of cell membrane proteins, integrins, which we know participate in the adhesion of cells to the extracellular matrix, in adhesion between cells and as bidirectional signal transducer mechanisms. In this work, we carried out studies of the interactions established between cardiac integrins α2ß1 and α5ß1 with different PSPy models by molecular docking studies and binding free energies (ΔGb) calculations. The models based on a previously reported PSPy molecule have three variable terminal chemical groups, with the purpose of exploring the differences in the type of interaction that will be established by modifying the position of an amino (-NH2), a hydroxyl (-OH), and a nitrile (C≡N) in (fixed) groups, as well as the length of the terminal chains (a long/short -NH2). A model with short chains for the -OH and -NH2 (lateral) group was the model with the best interactions with cardiac integrins. We experimentally verified the direct interaction of cardiomyocytes with the PSPy biomaterial observed in rat primary cultures, allowing us to validate the favorable interactions predicted by the computational analysis.

Groin pain of neurological origin as a differential diagnosis of femoroacetabular impingement.

BACKGROUND: To describe the experience in the diagnostic process and treatment of patients with groin pain (GP) of neurological origin due to entrapment of the iliohypogastric (IH), ilioinguinal (IL) and genitofemoral (GF) nerves in a hip preservation clinic. METHODS: Retrospective study of patients with GP of neurological origin confirmed with ultrasound-guided nerve block. Clinical outcomes were reported in 21 cases (age, 53.3 ± 15.9 years) treated with conservative treatment from January to December 2019, and in 9 patients (age 43.7 ± 14.6 years) who underwent neurectomy from January 2015 to December 2019. Pain intensity was assessed with a numerical rating scale (NRS) before starting the diagnostic process (Day 0) and at the end of follow-up. RESULTS: All cases reported pain on groin palpation. Half of these cases also reported a positive FADIR test (flexion, adduction, internal rotation) (15/30). On day 0, the intensity of pain in cases treated with conservative treatment was severe in 19 patients (NRS 7-10) and moderate in 2 (NRS 4-6), with a median improvement of 7 points (interquartile range [IQR] 5.5-8.0) at the end of follow-up (p < 0.001). In neurectomy group, a similar improvement in pain severity was (Day 0: 9 points [IQR 8.0-9.0]; end of follow-up: 0 points [IQR: 0-2.0]; p = 0.002). At the end of the study, 17/21 patients with conservative treatment and 7/9 with neurectomy were pain free or with mild pain (NRS < 3). CONCLUSIONS: In cases with PG of neurological origin, there is a high frequency of false positives in the FADIR test. Our findings suggest that neurectomy is a treatment option for patients in whom conservative treatment fails, providing significant pain relief.

Effect of a plasma synthesized polypyrrole coverage on polylactic acid/hydroxyapatite scaffolds for bone tissue engineering.

Composite biomaterials are solids that contain two or more different materials, combining the properties of their components to restore or improve the function of tissues. In this study, we report the generation of electrospun matrices with osteoconductive properties and porosity using the combination of a biodegradable polyester, polylactic acid (PLA), and hydroxyapatite (HA). Additionally, we report the effects of modifying these matrices through plasma polymerization of pyrrole on the growth and osteogenic differentiation of rabbit bone marrow stem cells. Cells were isolated, seeded and cultured on biomaterials for periods between 7 and 28 days. The matrices we obtained were formed by nano and microfibers containing up to 35.7 wt% HA, presenting a variety of apparent pore sizes to allow for the passage of nutrients to bone cells. Scanning electron microscopy showed that the fibers were coated with polypyrrole doped with iodine, and MTT assay demonstrated this increased cell proliferation and significantly improved cell viability due to the adhesive properties of the polymer. Our results show that PLA/HA/Pyrrole/Iodine matrices are favorable for bone tissue engineering.