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One step 3D printing of surface functionalized composite scaffolds for tissue engineering applications

Kotlarz M., Jordan R., Wegner E., Dobrzyński P., Neunzehn J., Lederer A., Wolf-Brandstetter C., Pamula E., Scharnweber D.

Acta of Bioengineering and Biomechanics

2018

Vol. 20, no. 2

35--45

A successful approach widely used in materials science to adapt approved materials to specific applications is to design their surface properties. A main challenge in this area is the development of processing routes enabling for a simple but efficient surface design of complex shaped geometries. Against this background, this work aimed at the implementation of self-assembly principles for surface functionalization of 3D-printed poly(lactic-co-glycolic acid) (PLGA)-based constructs with macro- and microporous geometries via precision extruding deposition. Methods: Three-component melts from PLGA, CaCO3 and amphiphilic polymers (poly(2-oxazoline) block copolymer) were printed and their bulk and surface properties were studied. Results: Melts with up to 30 mass % of CaCO3 could be successfully printed with homogeneously distributed mineral particles. PLGA degradation during the printing process was temperature and time dependent: the molecular weight reached 10 to 15% of the initial values after ca. 120 min of heat exposure. Filament surfaces from melts containing CaCO3 show an increasing microroughness along with increasing CaCO3 content. Surface roughness and amphiphilic polymer content improve scaffold wettability with both factors showing synergistic effects. The CaCO3 content of the melts affected the inner filament structure during in vitro degradation in PBS, resulting in a homogeneous mineral particle-associated microporosity for mineral contents of 20 mass % and above. Conclusions: These results provide novel insights into the behavior of three-component melts from PLGA, CaCO3 and amphiphilic polymers during precision extruding deposition and show for the first time that self-assembly processes can be used to tailor scaffolds surface properties under such processing conditions.

Organiczne związki fosfinowe, jako inhibitory korozji stali zbrojeniowej w betonie skażonym jonami chlorkowymi

Klakočar-Ciepacz M., Kotlarz M., Falewicz P.

Przegląd Budowlany

2014

R. 85, nr 5

40--42

W artykule przedstawiono wyniki badań metodą potencjodynamiczną i spektroskopii impedancyjnej (EIS) skuteczności ochrony przed korozją stali zbrojeniowej w roztworze symulującym ciecz porową betonu skażonego jonami chlorkowymi za pomocą opracowanego preparatu inhibitorowego. Preparat inhibitorowy jest mieszaniną kwasu dietyloaminometylo( heksa-metylenoiminometylo)fosfinowego, kwasu cytrynowego i siarczanu cynku. Stwierdzono, że opracowany preparat inhibitorowy chroni przed korozją stal zbrojeniową ze skutecznością 66,6% (obniża szybkość korozji do wartości 0,014 mm/rok), a charakter jego działania jest mieszany katodowo-anodowy.

The effectiveness of corrosion protection of the dietyloaminometylo(heksametylenoimino-metylo)phosphine acid and its mixture with citric acid and zinc sulfate in a pore simulating solution with Cl- ions for reinforcing bar was calculated by use both methods: the pototentiodynamic test and impedance spectroscopy (EIS). The effectiveness of corrosion protection for reinforcing bar by developed inhibitive mixture is 66.6% (corrosion rate 0,014 mm/yr.). The inhibitive mixture behaves as mixed inhibitor: cathodic-anodic.