Poly(3-hydroxybutyrate) (PHB) and Polycaprolactone (PCL) Based Blends for Tissue Engineering and Bone Medical Applications Processed by FDM 3D Printing

In the presented work, poly(3-hydroxybutyrate)-PHB-based composite blends for bone medical applications and tissue engineering are prepared and characterized. PHB used for the work was in two cases commercial and, in one case, was extracted by the chloroform-free route. PHB was then blended with poly(lactic acid) (PLA) or polycaprolactone (PCL) and plasticized by oligomeric adipate ester (Syncroflex, SN). Tricalcium phosphate (TCP) particles were used as a bioactive filler. Prepared polymer blends were processed into the form of 3D printing filaments. The samples for all the tests performed were prepared by FDM 3D printing or compression molding. Differential scanning calorimetry was conducted to evaluate the thermal properties, followed by optimization of printing temperature by temperature tower test and determination of warping coefficient. Tensile test, three-point flexural test, and compression test were performed to study the mechanical properties of materials. Optical contact angle measurement was conducted to determine the surface properties of these blends and their influence on cell adhesion. Cytotoxicity measurement of prepared blends was conducted to find out whether the prepared materials were non-cytotoxic. The best temperatures for 3D printing were 195/190, 195/175, and 195/165 degrees C for PHB-soap/PLA-SN, PHB/PCL-SN, and PHB/PCL-SN-TCP, respectively. Their mechanical properties (strengths similar to 40 MPa, moduli similar to 2.5 GPa) were comparable with human trabecular bone. The calculated surface energies of all blends were similar to 40 mN/m. Unfortunately, only two out of three materials were proven to be non-cytotoxic (both PHB/PCL blends)

A Simple Drug Delivery System for Platelet-Derived Bioactive Molecules, to Improve Melanocyte Stimulation in Vitiligo Treatment

Vitiligo is the most common depigmentation disorder of the skin. Currently, its therapy focuses on the halting of the immune response and stimulation of the regenerative processes, leading to the restoration of normal melanocyte function. Platelet-rich plasma (PRP) represents a safe and cheap regenerative therapy option, as it delivers a wide spectrum of native growth factors, cytokines and other bioactive molecules. The aim of this study was to develop a simple delivery system to prolong the effects of the bioactive molecules released from platelets. The surface of electrospun and centrifugally spun poly--caprolactone (PCL) fibrous scaffolds was functionalized with various concentrations of platelets; the influence of the morphology of the scaffolds and the concentration of the released platelet-derived bioactive molecules on melanocytes, was then assessed. An almost two-fold increase in the amount of the released bioactive molecules was detected on the centrifugally spun vs. electrospun scaffolds, and a sustained 14-day release of the bioactive molecules was demonstrated. A strong concentration-dependent response of melanocyte to the bioactive molecules was observed; higher concentrations of bioactive molecules resulted in improved metabolic activity and proliferation of melanocytes. This simple system improves melanocyte viability, offers on-site preparation and is suitable for prolonged topical PRP administration

Laterální mezitělová fúze na bederní páteři provedena na prasečím modelu s biologicky resorbovatelným keramicko/biopolymerním hybridním implantátem obohaceným o hyperstabilní růstový faktor fibroblastů 2

An experimental animal study was designed to investigate the intervertebral fusion efficiency and safety of a bioresorbable ceramic/biopolymer hybrid implant enriched with FGF2-STAB(R) in comparison with a tricortical bone autograft used as a gold standard. Twenty-four experimental pigs underwent L2/3 discectomy with implantation of either the tricortical iliac crest bone autograft or the bioresorbable hybrid implant (BHI) followed by lateral intervertebral fixation. The quality of spinal fusion was assessed by micro-computed tomography (micro-CT), biomechanical testing, and histological examination at both 8 and 16 weeks after the surgery.Experimentální studie na zvířatech byla navržena tak, aby zkoumala účinnost a bezpečnost meziobratlové fúze a biologicky resorbovatelného hybridního implantátu z keramiky/biopolymeru obohaceného o FGF2-STAB (R) ve srovnání s trikortikálním kostním autograftem používaným jako zlatý standard. Dvacet čtyři experimentálních prasat podstoupilo discektomii L2/3 s implantací buď trikortikálního autograftu kosti kyčelní, nebo bioresorbovatelného hybridního implantátu (BHI) s následnou laterální intervertebrální fixací. Kvalita spinální fúze byla hodnocena mikropočítačovou tomografií (mikro-CT), biomechanickým testováním a histologickým vyšetřením v 8. a 16. týdnu po operaci