At 02.12.2011 I conducted a lecture about my master thesis and a short introduction into my research during PhD studies. Title of the first part of the presentation was: “Bioactive glass/poly(L-lactide-co-glycolide) composite scaffolds for bone tissue engineering”, the second part of the presentation covered topic: “Biodegradable magnesium alloys for medical applications”.

In connection with the development of all fields of medicine, especially in connection with the emergence of regenerative medicine, arose the need to produce a new generation of biomaterials. New materials must fulfill higher demands, all materials have to be biocompatible and more often - bioactive. Currently, if patient’s tissue is damaged, there are two options: transplantation or implantation. Organ transplantation is the moving of an organ from one body to another, or from a donor site on the patient's own body, for the purpose of replacing the recipient's damaged or absent organ. Implantation takes place, when medical device made of biomaterials is placed into the patient. Both approaches have their advantages and disadvantages.

Due to the development of biomaterials engineering, it has become possible to obtain a bioactive material. Thanks to this, now we have a new, third option - the application of a biomaterial, which replaces the missed tissue function and stimulates the regeneration of damaged tissue around prostheses. Such bone inductive materials are often made of calcium phosphates, e.g. hydroxyapatite or bioglass, because these materials directly connect to the bone. Equally interesting materials are aliphatic polyesters – resorbable polymers; inside the human body they undergo hydrolysis and products of their decomposition are removed together with metabolic products.

Every material, which is considered to be a biomaterial, must satisfy certain physical, mechanical and chemical behavior requirements and also be characterized as biocompatible. For example, the material must be strong enough to bear physiological load, resist undesired degradation or corrosion, be not carcinogenic, not immunogenic, antileukotactic, and so on. Many factors, such as implant size, shape, material composition, surface wettability, roughness and charge influence implant biocompatibility.

The purpose of this study was to manufacture composite materials based on resorbable polymer (PLGA) with addition of sol-gel derived bioglasses from the system CaO-SiO2-P2O5 and in vitro evaluation of these scaffolds. As a result, polymer-bioglass composites containing 10 vol. % and 20 vol. % of two types of bioglasses were prepared. Their bioactive properties were assessed by measuring of the ability to create hydroxyapatite layers on the surface when in contact with simulated body fluid (SBF). Porosity, water absorption and kinetics of degradation of the scaffolds were estimated. In addition, bioactivity of the scaffolds was evaluated in cell culture with MG-63 cell line.

During my PhD studies I want to focus on the evaluation of biodegradable magnesium alloys for bone implants. These alloys, in comparison with PLGA/bioglass scaffolds, have strength and Young’s modulus close to the natural bone. However, the corrosion ratio and hydrogen gas production during the degradation process need to be investigated.

My research in November:

During the second month of my PhD studies at the Institute of Metallurgy and Material Polish Academy of Sciences I paid attention on preparation of a lecture about “Bioactive glass/poly(L-lactide-co-glycolide) composite scaffolds for bone tissue engineering”. In the second part of the presentation I gave the introduction into biodegradable magnesium alloys. In November I also have made and literature studies connected with biodegradation of magnesium alloys. Together with my supervisor, we have choosen the probable candidate for our research: Mg-Zn-Ca (3-5 wt% Zn, 0.5-1.5 wt% Ca).

Between 14th and 18th of November I participated in “PhD School on nanoanalysis using finely focused ion and electron beams” in Gabriel Lippmann Center in Luxemburg.

In November I studied the stability of homogeneous Zn(II)-Sn(II)-Mo(VI) citrate solutions and theelectrochemical properties of citrate complexes presented in examinated solutions by cyclic voltammetry method and UV-Vis spectroscopy. I conducted research in the following solutions:
1) 0,25 M Cit + 0,02 M Na2MoO4; pH=5;
2) 0,25 M Cit + 0,1 M Na2MoO4; pH=5;
3) 0,25 M Cit + 0,24 M Na2MoO4; pH=5;
4) 0,65 M Cit + 0,02 M Na2MoO4; pH=5;
5) 0,65 M Cit + 0,1 M Na2MoO4; pH=5;
6) 0,65 M Cit + 0,24 M Na2MoO4; pH=5;
7) 0,25 M Cit + 0,02 M Na2MoO4 + 0,16 ZnSO4; pH=5;
8) 0,25 M Cit + 0,1 M Na2MoO4 + 0,16 ZnSO4; pH=5;
9) 0,25 M Cit + 0,24 M Na2MoO4 + 0,16 ZnSO4; pH=5;
10) 0,65 M Cit + 0,02 M Na2MoO4 + 0,16 ZnSO4; pH=5;
11) 0,65 M Cit + 0,1 M Na2MoO4 + 0,16 ZnSO4; pH=5;
12) 0,65 M Cit + 0,24 M Na2MoO4 + 0,16 ZnSO4; pH=5;
13) 0,65 M Cit + 0,24 M Na2MoO4 + 0,08 ZnSO4; pH=5;
14) 0,65 M Cit + 0,24 M Na2MoO4 + 0,32 ZnSO4; pH=5;
15) 0,65 M Cit + 0,24 M Na2MoO4 + 0,16 ZnSO4 + 0,12Na2SO3; pH=5;

My Research:

The main goal was to complete series of studies with scanning electron microscopy using technique - EBSD (electron backscatter diffraction) - creating orientation maps (microstructure) for aluminum alloy AA1050. Unfortunately, my goal was not achieved at 100% due to the time-consuming measurements and the process of preparing samples to the research. I have made several orientations maps: for material in deformed state - after ECAP C6x in cross-sections: ND-TD and the ND-RD; for material in deformed state - after ECAP A6x in the cross-section: ND-RD; and for the initial state in cross-section: TD-RD. Thus, to complete the series of the study with EBSD / SEM left: the initial state in the cross-section: TD-RD and additionally for material in deformed state after ECAP A3x in cross-sections: ND-TD and ND-RD. These studies should be done before the end of the year.

My participation in PAS Seminars:

- Dr Eng. W. Wajda: ‘Simulation of microstructure and texture development using Digital Material Representation and 'Crystal Plasticity’ model’
- MSc. Eng. P. Wyzga: ‘Unconventional methods of producing TiB2-TiN composites’

Main studies carried out during November:

- analysis of the results obtained so far

- participation in the European PhD School on "Nanoanalysis using focussed ion and electron beams" – Week 1: "Secondary Ion Mass Spectrometry (SIMS), Transmission Electron Microscopy (TEM), Auger Electron Spectroscopy (AES): a comprehensive overview" organized by Centre de Recherche Public - Gabriel Lippmann w Belvaux, Luksemburg. Lectures presenting an overview of these three analytical techniques were connected with practical sessions in front of the instruments dedicated to each method.

- participation in seminar given by MSc. Eng. Pawel Kuczera with the title: „Structure of decagonal quasicrystals Al-Cu-Me (Me = Co, Rh, Ir)”. During seminar following information were given: the problem of thermodynamic stability of quasicrystalline phases, a method of preparing single crystal samples, X-ray diffraction experiments, charge-flipping algorithm