Lauth, Victor Rafael
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Preferred name
Lauth, Victor Rafael
Official Name
Lauth, Victor Rafael
Alternative Name
Lauth, Victor R.
Lauth, V. R.
Lauth, Victor
Lauth, V.
ORCID
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Item-typ:Veröffentlichung, An evaluation of colloidal and crystalline properties of CaCO3 nanoparticles for biological applicationsBiodegradable calcium carbonate carriers are a promising and safe nanoparticle platform which might enable various applications as an engineered nanomaterial in health care, food and cosmetics. However, engineered nanoparticles can exhibit new forms of toxicity that must be carefully evaluated before being widely adopted in consumer products or novel drug delivery systems. To this end, we studied four common calcium carbonate particle systems (calcite nanoparticles, amorphous sub-micrometer and vaterite sub-micrometer and micrometer particles) and compared their behavior in biological medium and in cell culture experiments. The thermodynamically stable calcite phase is shown to maintain its morphological features as no phase transformation occurs. Size- and time-dependent phase transformation of the less stable vaterite particles are observed within 96h in cell medium. The protein serum albumin can be an effective inhibitor of phase-transition and it is shown to improve colloidal stability. The impact of the biological environment goes beyond protein-corona formation, as we observed rapid dissolution of amorphous particles in high ionic strength cell medium, but not in Millipore water. Cellular responses of human osteoblasts against CaCO3 particles indicate that increased intracellular calcium ions improve viability and that particle internalization is not size-dependent. Useful insights for designing CaCO3-based delivery systems are provided and also corroborate to the idea that intrinsic material properties as well as environmental conditions are of relevance for the successful implementation of dispersed CaCO3 particles in drug delivery systems and in other applications.Wissenschaftlicher ArtikelBand:78103 204 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Micromolding of Calcium Carbonate Using a Bio-Inspired, Coacervation-Mediated Process(Wiley, 2013-03-17); ; ; ; Based on a novel approach that takes into account the coacervation of calcium and poly(acrylic acid) (PAA), we were able to biomimetically produce molded micropatterned parts from amorphous calcium carbonate (ACC) particles. We studied the time- and concentration-dependent growth of Ca2+/PAA coacervate droplets using dynamic light scattering (DLS) and turbidity measurements. Applying these results for the generation of high amounts of unstable ACC particles, we were able to produce slurries that could be molded into micropatterned casts. The obtained slurries contained both micrometer sized ACC particles and smaller nano-sized particles. When both types of particles were used for molding, materials with a high surface roughness could be produced, while the micropatterns of the molds could not be reproduced properly. However, by removing the bigger particles from the slurry using only the smaller, unstable, ACC particles, good reproduction of the micropatterns could be achieved, yielding smooth surfaces with a high surface area. The processing route represents a versatile platform for the bottom-up preparation of micropatterned ceramics on the basis of calcium carbonate.Wissenschaftlicher ArtikelBand:96Heft:3114 121 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Calcium carbonate colloidal particles as delivery vehicles to biological systems(2017-10-19); ; ; Colloidal systems are increasingly being used in consumer products. Special interest is drawn to their application as delivery vehicles. To this end, there is the need of novel synthesis methods to produce colloids with tailored size and morphology in absence of harsh conditions and toxic constituents. One material for such purposes is calcium carbonate, as it can be synthesized in mild conditions besides being endogenous to the body, safe, biodegradable and biocompatible. Yet, there are still limitations that could hinder its use as a viable delivery system, like the morphological and size control, particle instability in aqueous solutions and the sustained release of encapsulated molecules. In this thesis, these aspects are studied in detail and new strategies are explored for the preparation of suitable colloidal carriers with biocompatible cellular interactions. To this purpose, distinct principles that govern biomineralization and complex coacervation are translated to synthetic systems and assessed in vitro by means of monoculture cellular experiments. These principles include: (1) the use of charged proteins and polymers as the assembling components during the complex coacervation; (2) the use of polyelectrolytes molecules to direct the mesoscale assembly of anisotropic nanoparticles; and (3) the study on how the physical and colloidal properties of CaCO3 systems can control particle-cellular interactions. The studies focused on the loading ability, colloidal and crystal phase stability as well as cellular outcome.Dissertation453 153