Bio-nanomaterials and regenerative medicine

Resume : We present high-precision laser processing of biodegradable polymers toward applications in drug delivery and tissue engineering. We have been studying enhanced optical near field and scattered far field excited by femtosecond laser pulse. The interaction of a femtosecond laser pulse and biodegradable microcapsules generate an enhanced-ultrafast optical field in the vicinity or inside multiple biodegradable microcapsules. Nanoperforation of hollow polymer microcapsules was demonstrated by the optical field generated at the shell of the capsules by the irradiation of unfocused infrared femtosecond laser without any doping with metals or dyes. The present method has the potential to realize novel light-triggered controlled drug release. The interference of scattered far field and incident waves enables to fabricate ripple structure on a biodegradable polymer surface. We demonstrated ripple structure formation on a biodegradable polymer, poly-L-lactic acid (PLLA), film by using femtosecond laser pulses. High-spatial frequency periodic structure whose periodicity is approximately 100 nm was fabricated on the surface of PLLA film, which would contribute to scaffold fabrication in tissue engineering by controlling cell adhesive properties on the surface of biodegradable polymers.

Resume : Piezoelectric materials, including collagenous biomaterials, organic bioinspired peptide nanomaterials, deoxyribonucleic acid nucleobase crystals, and transparent biocompatible ferroelectric substrates have numerous potential applications in sensing, energy harvesting, and tissue engineering. Recent progress in understanding the origin and role of piezoelectricity and possible ferroelectricity in such functional biomaterials using piezoresponse force microscopy (PFM) and the biocompatibility and proliferation of osteoblast cells on ferroelectric lithium niobate crystals will be discussed. The role of pH and moisture content on electromechanical coupling in type I collagen and piezoelectricity in type II collagen will be presented. Thymine and other nucleobase microcrystals grown from solution during evaporation also exhibit piezoelectricity, and in some cases contain domains which appear to switch via external field, hinting at possible ferroelectric properties. Much like the structurally-similar peptide nanotubes, dried peptide hydrogels are also found to be piezoelectric. In addition, ferroelectric lithium niobate, which has a permanent polarization (in the z-cut direction) is reported as a novel platform to study the effect of surface charge for improving osseointegration via cell proliferation and mineralization assays. The outlook for future measurements and applications of piezoelectric biomaterials and biocompatible ferroelectric substrates will be outlined.

Resume : Nanoparticles emitting light with energy higher than the excitation radiation are gaining attention as a new generation of potential probes for many important applications in biomedicine. In particular, they can be applied for the nanoscale imaging of biological objects. Presence of Yb ions, as a sensitizer, improves the efficiency of the Er emission in the upconversion (UC) process. However, the efficiency of the green emission process of the Er-Yb doped oxides (Er3 , 550 nm, 2H11/2→4I15/2, 2S3/2→4I15/2) is still relatively low. There is a need to find a way to increase the efficiency resulting from the upconversion process. In this work we demonstrate that this aim can be achieved through co-doping with Mo. For the preparation of the oxide materials Gd2O3:Er,Yb,Mo we applied a homogeneous precipitation method in the presence of urea followed by a high temperature (900 oC) annealing at air. The advantages of this method consist in a low temperature of the synthesis and in a relatively low production cost. As a product, we obtained spherical nanoparticles with sizes from 50 to 150 nm, and desired enhanced green emissions due to higher efficiency of energy transfer from Yb3 - MoO42- dimer to Er than in the case of pure Yb doping. To investigate their efficacy, these nanoparticles were used as luminescent labels in selected biological materials. Upconverting, non-functionalized, Gd2O3:Er,Yb,Mo nanoparticles, incubated with HeLa and glial astrocytes cell, were endocytosed. Acknowledgements: The research was partially supported by the EU within ERD Fund, through the Innovative Economy grant (POIG.01.01.02-00-008/08) and by the grant from the Polish National Centre for Research and Development NR13004704, the Polish National Science Center NN 303 663 940 and the Center of Excellence. This work has been done in the NanoFun laboratories co-financed by the European Regional Development Fund within the Innovation Economy Operational Programme, the Project No. POIG.02.02.00-00-025/09/. This research has been co-financed with the European Union funds by the European Social Fund and the project WELCOME Hybrid nanostructures as a stepping stone towards efficient artificial photosynthesis

Resume : We report on the nanostructured composite coatings with bioactive silicate glass and poly (methyl-methacrylate) for biomimetic implant applications. Bioglasses and composite bioglasses – poly(methyl-methacrylate) thin films films grown onto medical grade stainless steel 316L substrates using a pulsed laser UV KrF* (248 nm wavelength, 25 ns pulse duration, 10 Hz frequency repetition rate) excimer laser source. We aimed for the elimination of the inconvenience caused by corrosion of stainless steel implants in human body by coating with thin films of bioactive glasses and/ or with polymer-bioactive glasses nanostructures. For the preparation of simple PLD targets, we selected two types of bioglasses, the difference between them consisting in the SiO2 content, which is slightly below (in the case of BG57, containing 56.5% SiO2, 11% Na2O, 3% K2O, 15% CaO, 8.5% MgO, 6% P2O5 in wt.%) and respectively above (in the case of BG61 containing 61.1% wt SiO2, 10.3% wt Na2O, 2.8% wt K2O, 12.6% wt CaO, 7.2% wt MgO, 6% wt P2O5). The threshold value of 60% corresponds to significant changes in bioactivity and degradability. The PLD depositions were carried out in a dynamic flux of oxygen. The best regime of deposition was found for the next conditions: 13 Pa O2 pressure, 400°C substrate temperature and 10,000 subsequent laser pulses for each film. PMMA (poly (methyl-methacrylate)) exhibits a good impact strength, superior to glass and for the MAPLE depositions we combined it with bioglasses and the composite targets were suspended in a 3% solution in chloroform. For comparation, we prepared MAPLE targets from simple PMMA polymer. Our intention is to produce biomimetic coatings more resistant to scratching by adding to PMMA bioglass particles which also exhibit the ability to chemically bond to both bone and tissue. Potentiodynamic polarization measurements evidenced for bare OL an intensive corrosion, but BG57 and BG57 - PMMA coated OL samples showed a substantially higher resistance to corrosion than bare OL. The best shielding was demonstrated in case of BG61-PMMA coating. The nanostructured PMMA-BG61/316L coating ensures the preservation of the stainless steel surface bioactivity and serves as an efficient shield against corrosion. Our results suggest the use of stainless steel coated with bioglass-based and especially with PMMA-bioglass laser deposited thin films as a challenging alternative for production of reliable and cheap human implants and prostheses.

Resume : Curcumin is one of the polyphenols, which has been known for its medicinal use since long time. Curcumin shows poor solubility and low absorption, and therefore, use of curcumin as nanoparticles is beneficial due to their greater solubility and absorption. The main aim of the present study was the formation of curcumin nanoparticles, evaluation of antibacterial activity against human pathogenic bacteria, and formulation of curcumin nanoparticles-based cream. We synthesized curcumin nanoparticles by sonication method. The synthesis of curcumin nanaoparticles was assessed for their solubility in water and by UV- visible spectrophotometry. Further, the nanopaticles were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Transmission electron microscopy (TEM), Nanoparticle Tracking and Analysis (NTA) and Zeta Potential analysis. In vitro antibacterial activity of curcumin nanoparticles was evaluated against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The cream containing curcumin nanoparticles was found to be effective against human bacterial pathogens and hence can be used for the dermatological bacterial infections.