Bartosz F. Grześkowiak

Antimicrobial electrospun poly(ε-caprolactone) scaffolds for gingival fibroblast growth

This study discusses the value of polymer electrospun materials in three-dimensional (3D) scaffolds and antibacterial wound dressings for potential dental applications. Polycaprolactone (PCL) and polyvinylpyrrolidone (PVP) nanofibers were used as bases for gingival fibroblast (HGF-1 cell line) growth. HGF-1 cells cultured on both types of nanofibers were found to have normal morphology and growth by selective staining of the nuclei and cytoskeleton. The nanofibers were synthesized on different collectors to obtain a random or parallel alignment. Cell growth was observed along the nanofibers. In addition, antibiotics were incorporated within the nanofibers and studied by means of Raman spectroscopy and differential scanning calorimetry. The release profile of the antibiotics was determined by broad band dielectric measurements. The drug was found to be released by Fickian diffusion. The WST-1 test found PCL and PCL/ampicillin nanofibers to have minimal cytotoxicity. The antibacterial activity of materials containing ampicillin was evaluated by zone inhibition against a selected oral strain of Streptococcus sanguinis. The bacterial growth was inhibited by antibiotic release from PCL/ampicillin mats.

Size and shape-dependent cytotoxicity profile of gold nanoparticles for biomedical applications

Metallic nanoparticles, in particular gold nanoparticles (AuNPs), offer a wide spectrum of applications in biomedicine. A crucial issue is their cytotoxicity, which depends greatly on various factors, including morphology of nanoparticles. Because metallic nanoparticles have an effect on cell membrane integrity, their shape and size may affect the viability of cells, due to their different geometries as well as physical and chemical interactions with cell membranes. Variations in the size and shape of gold nanoparticles may indicate particular nanoparticle morphologies that provide strong cytotoxicity effects. Synthesis of different sized and shaped bare AuNPs was performed with spherical (~ 10 nm), nanoflowers (~ 370 nm), nanorods (~ 41 nm), nanoprisms (~ 160 nm) and nanostars (~ 240 nm) morphologies. These nanostructures were characterized and interacting with cancer (HeLa) and normal (HEK293T) cell lines and cell viability tests were performed by WST-1 tests and fluorescent live/dead cell imaging experiments. It was shown that various shapes and sizes of gold nanostructures may affect the viability of the cells. Gold nanospheres and nanorods proved to be more toxic than star, flower and prism gold nanostructures. This may be attributed to their small size and aggregation process. This is the first report concerning a comparison of cytotoxic profile in vitro with a wide spectrum of bare AuNPs morphology. The findings show their possible use in biomedical applications.Graphical Abstract

In vitro genotoxicity and cytotoxicity of polydopamine-coated magnetic nanostructures

Synthesis of magnetic nanoparticles and magnetic nanoclusters was performed by the co-precipitation method or solvothermal synthesis, respectively, followed by oxidative polymerization of dopamine, resulting in a polydopamine (PDA) shell. The nanomaterials obtained were described using TEM, FTIR and magnetic measurements. For the first time, cyto- and genotoxicity studies of polydopamine-coated nanostructures were performed on cancer and normal cell lines, providing in-depth insight into the toxicity of such materials. The tests conducted, e.g. ROS, apoptosis and DNA double-break of the nanomaterials obtained revealed the low toxicity of these structures. Thus, these results prove the biocompatibility and low genotoxicity of these materials and provide new data on the toxicity of PDA-coated materials, which is of great importance for their biomedical application.

ZnO@Gd2O3 core/shell nanoparticles for biomedical applications: Physicochemical, in vitro and in vivo characterization

The chemical composition of nanoparticles (NPs) may be so designed as to provide measurability for numerous imaging techniques in order to achieve synergistic advantages. Innovative and unique structure of the core/shell ZnO@Gd2O3 NPs possesses luminescent and magnetic properties, and is expected that they will become a new generation of contrast agents for Magnetic Resonance Imaging (MRI) and nanocarriers for theranostics. Thus, by surface biofunctionalization, it is possible to indicate particular nanoparticle compositions which provide efficient imaging, targeted drug delivery, and biocompatibility. Novel ZnO@Gd2O3 NPs were synthesized and biofunctionalized by folic acid (FA) and doxorubicin (Doxo) to provide target and anticancer functions. Physicochemical analyses of the nanoparticles were performed. The biological study included a cytotoxicity in vitro, cellular distribution evaluation, as well as toxicity analyses, performed for the first time, on the in vivo zebrafish (Danio rerio) model. Nanoparticles were found to be effective double-function biomarkers (MRI T2 contrast agents, fluorescent imaging). The biological study showed that ZnO@Gd2O3 and ZnO@Gd2O3@OA-polySi@FA NPs are biocompatible in a particular concentration ranges. Conjugation with folic acid and/or doxorubicin resulted in effective drug delivery targeting. The in vivo results described the toxicology profile toward the zebrafish embryo/larvae, including new data concerning the survival, hatching ratio, and developmental malformations.

Cyclodextrin-Based Magnetic Nanoparticles for Cancer Therapy

Polydopamine (PDA)-coated magnetic nanoparticles functionalized with mono-6-thio-β-cyclodextrin (SH-βCD) were obtained and characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Nuclear and Magnetic Resonance Imaging (NMR and MRI), and doxorubicin (DOXO)-loading experiments. The liver cancer cellular internalization of DOXO-loaded nanoparticles was investigated by confocal imaging microscopy. Synthesized nanomaterials bearing a chemotherapeutic drug and a layer of polydopamine capable of absorbing near-infrared light show high performance in the combined chemo- and photothermal therapy (CT-PTT) of liver cancer due to the synergistic effect of both modalities as demonstrated in vitro. Moreover, our material exhibits improved T2 contrast properties, which have been verified using Carr-Purcell-Meiboom-Gill pulse sequence and MRI Spin-Echo imaging of the nanoparticles dispersed in the agarose gel phantoms. Therefore, the presented results cast new light on the preparation of polydopamine-based magnetic theranostic nanomaterials, as well as on the proper methodology for investigation of magnetic nanoparticles in high field MRI experiments. The prepared material is a robust theranostic nanoasystem with great potential in nanomedicine.

Cytotoxicity and imaging studies of β-NaGdF4:Yb3+Er3+@PEG-Mo nanorods

Multimodal imaging based on nanostructures has become a subject of interest for numerous biomedical laboratories. The main focus was placed on applying nanocrystals for the purpose of two types of clinical imaging (contrast and fluorescent agents) due to their excellent luminescence and/or paramagnetic properties. Such systems should also be characterized by low toxicity and high cellular uptake efficiency. Since bare rare earth fluoride nanocrystals influence the cell membrane integrity, it is expected that their coatings will improve biocompatibility profile, as well as increase hydrophilicity, dispersion and chemical stability. Hence, by synthesis of β-NaGdF4:Yb3+Er3+ nanorods (NRs) coated with noncovalently bounded polyethylene glycol monooleate (PEG-Mo), it should be possible to obtain multimodal imaging biomarkers meeting established criteria. Synthesis of β-NaGdF4:Yb3+Er3+@PEG-Mo NRs was performed by the co-precipitation method. These nanostructures were characterized in terms of their size, morphology, zeta potential, magnetic and optical properties as well as their cytotoxicity profile and cellular internalization was evaluated. It was shown that the shape and size of nanocrystals, namely 20 nm nanorods, present generally accepted parameters for biomedical purpose. Ligand attraction of PEG-Mo 860 resulted in the encapsulation of oleic acid coated NRs and formation of hydrophilic bilayer. Superparamagnetic and luminescence properties were highly efficient. Cytotoxic profiles of normal and cancer cell lines were low and determined by dose and time. Cellular uptake was confirmed by the presence of upconversion luminescence in cell interior. These findings are showing multimodal imaging properties of rod shaped β-NaGdF4:Yb3+Er3+@PEG-Mo NRs which may be useful in some biomedical applications.

Cilostazol-loaded electrospun three-dimensional systems for potential cardiovascular application: Effect of fibers hydrophilization on drug release, and cytocompatibility

Currently marketed drug-eluting stents are non-selective in their anti-restenotic action. New active substance introduction to polymeric stents and vascular grafts can promote early re-endothelialization, crucial in preventing implant restenosis. Additionally, managing material hydrophobicity by blending synthetic polymers limits adverse effects on bulk properties and controls active substance release. However, the influence of hydrophilic synthetic polymer on human cells in the cardiovascular system remains to be determined. In this report, effects of both poly(ε-caprolactone) (PCL) fibers hydrophilization with Pluronic P123 (P123) and cilostazol (CIL) loading were studied. Physicochemical and mechanical properties of electrospun tubular structures produced from PCL and PCL/P123 fibers with and without CIL were investigated and compared. Release profiles studies and in vitro cell proliferation assays of electrospun materials were conducted. It was found that P123 located near the surface of electrospun fibers increased the rate of CIL release. PCL formulation sustained human umbilical vein endothelial cells (HUVEC) growth for 48 h. Despite improved hydrophilicity, PCL/P123 formulations were found to reduce HUVEC viability. Both PCL and PCL/P123 materials reduced primary aortic smooth muscle cells (PASM) viability after 48 h. In PCL formulations containing CIL, drug release caused a decrease in PASM viability. P123 blending with PCL was found to be as a useful pre-fabrication technique for modulating surface hydrophobicity of electrospun materials and the release profile of incorporated active substance. The cytotoxicity of P123 was evaluated to improve the design of drug-loaded vascular grafts for cardiovascular applications.

Dendrimer based theranostic nanostructures for combined chemo- and photothermal therapy of liver cancer cells in vitro

Here we report the synthesis of multifunctional nanocarriers based on PAMAM dendrimers generation (G) 4.0, 5.0 and 6.0 fixed to polydopamine (PDA) coated magnetite nanoparticles (Fe3O4). Synthesized nanoplatforms were characterized by transmission electron microscopy (TEM), the electrokinetic (zeta) potential, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and magnetic resonance imaging (MRI). Further, we show as a proof of concept that nanocarriers functionalized with G 5.0 could be successfully applied in combined chemo- and photothermal therapy (CT-PTT) of the liver cancer cells. The cooperative effect of the modalities mentioned above led to higher mortality of cancer cells when compared to their individual performance. Moreover, the performed in vitro studies revealed that the application of dual therapy triggered the desired cell death mechanism-apoptosis. Furthermore, performed tests using Magnetic Resonance Imaging (MRI) showed that our materials have competitive contrast properties. Overall, the functionality of dendrimers has been extended by merging them with magnetic nanoparticles resulting in multifunctional hybrid nanostructures that are promising smart drug delivery system for cancer therapy.