22 research outputs found
Design, synthesis, and preliminary evaluation for Ti-Mo-Zr-Ta-Si alloys for potential implant applications
Considering the future trends of biomaterials, current studies are focused on the corrosion
resistance and the mechanical properties of new materials that need to be considered in the
process of strengthening alloys with additive non-toxic elements. Many kinds of titanium alloys with
different biocompatible elements (Mo, Si, Zr, etc.,) have been recently developed for their similar
properties with human bone. Four new different alloys were obtained and investigated regarding
their microstructure, mechanical, chemical, and biological behavior (in vitro and in vivo evaluation),
the alloys are as follows: Ti15Mo7Zr15Ta, Ti15Mo7Zr15Ta0.5Si, Ti15Mo7Zr15Ta0.75Si, and
Ti15Mo7Zr15Ta1Si. There were changes with the addition of the silicon element such as the hardness
and the modulus of elasticity increased. An MTT assay confirmed the in vitro cytocompatibility of
the prepared alloys
Development and characterisation of microporous biomimetic scaffolds loaded with magnetic nanoparticles as bone repairing material
Fine-tuning of the scaffolds structural features for bone tissue engineering can be an efficient approach to
regulate the specific response of the osteoblasts. Here, we loaded magnetic nanoparticles aka superparamagnetic
iron oxide nanoparticles (SPIONs) into 3D composite scaffolds based on biological macromolecules (chitosan,
collagen, hyaluronic acid) and calcium phosphates for potential applications in bone regeneration, using a
biomimetic approach. We assessed the effects of organic (chitosan/collagen/hyaluronic acid) and inorganic
(calcium phosphates, SPIONs) phase over the final features of the magnetic scaffolds (MS). Mechanical properties,
magnetic susceptibility and biological fluids retention are strongly dependent on the final composition of
MS and within the recommended range for application in bone regeneration. The MS architecture/pore size can
be made bespoken through changes of the final organic/inorganic ratio. The scaffolds undertake mild degradation
as the presence of inorganic components hinders the enzyme catalytic activity. In vitro studies indicated
that osteoblasts (SaOS-2) on MS9 had similar cell behaviour activity in comparison with the TCP control. In vivo
data showed an evident development of integration and resorption of the MS composites with low inflammation
activity. Current findings suggest that the combination of SPIONs into 3D composite scaffolds can be a promising
toolkit for bone regeneration
Advanced 3D Magnetic Scaffolds for Tumor-Related Bone Defects
The need for bone substitutes is a major challenge as the incidence of serious bone disorders is massively increasing, mainly attributed to modern world problems, such as obesity, aging of the global population, and cancer incidence. Bone cancer represents one of the most significant causes of bone defects, with reserved prognosis regarding the effectiveness of treatments and survival rate. Modern therapies, such as hyperthermia, immunotherapy, targeted therapy, and magnetic therapy, seem to bring hope for cancer treatment in general, and bone cancer in particular. Mimicking the composition of bone to create advanced scaffolds, such as bone substitutes, proved to be insufficient for successful bone regeneration, and a special attention should be given to control the changes in the bone tissue micro-environment. The magnetic manipulation by an external field can be a promising technique to control this micro-environment, and to sustain the proliferation and differentiation of osteoblasts, promoting the expression of some growth factors, and, finally, accelerating new bone formation. By incorporating stimuli responsive nanocarriers in the scaffold’s architecture, such as magnetic nanoparticles functionalized with bioactive molecules, their behavior can be rigorously controlled under external magnetic driving, and stimulates the bone tissue formation
Chondrocytes isolation from hyaline cartilage by continuous monitoring method
Background: Articular cartilage has poor regenerative capacities. Numerous cartilage repair techniques are known, including implantation of autologous
chondrocytes.
Material and methods: From 18 rabbits pieces of cartilage were harvested from femoral condyle. Minced cartilage was treated with 0.25% trypsin-EDTA.
In the 1st group (n=9) the cartilage was digested with 0.6% collagenase in 15 ml tubes by shaking in incubator at 37°C, 5%CO2. In the 2nd group (n=9)
digestion was performed in 25cm2 cell culture flasks placed on the lateral side, monitoring the process under a microscope after 120 minutes. The isolated
cells were cultured to a 80-90% confluence. The chondrocytes were identified using histochemical staining after culturing for 16 days in overconfluence.
Results: Chondrocytes isolation in the 1st group lasted a fixed 360 minutes, in the 2nd group – 140±10 minutes. In the 1st group were isolated 9.2x104±3.1x104
chondrocytes with a viability of 85.36±16.41%, but in the 2nd group – 1.6x105±3.4x104 chondrocytes with a viability of 98.09±3.85%. The mean period of
cell culture in the 1st group was 15±2 days, in the 2nd group – 11±3 days. In first passage of the 1st group were obtained – 1.2x106 ±4.3x105 chondrocytes
and in the 2nd group – 2.92x106 ±3.6x105 chondrocytes. The secreted extracellular matrix by chondrocytes was stained specifically for cartilaginous tissue.
Conclusions: The method used for chondrocytes isolation has a direct impact on the number of isolated cells, their viability, but also upon the culture
period and the number of cells obtained during the first passage
Transcutaneous Drug Delivery Systems Based on Collagen/Polyurethane Composites Reinforced with Cellulose
Designing composites based on natural polymers has attracted attention for more than a decade due to the possibility to manufacture medical devices which are biocompatible with the human body. Herein, we present some biomaterials made up of collagen, polyurethane, and cellulose doped with lignin and lignin-metal complex, which served as transcutaneous drug delivery systems. Compared with base material, the compressive strength and the elastic modulus of biocomposites comprising lignin or lignin-metal complex were significantly enhanced; thus, the compressive strength increased from 61.37 to 186.5 kPa, while the elastic modulus increased from 0.828 to 1.928 MPa. The release of ketokonazole from the polymer matrix follows a Korsmeyer–Peppas type kinetics with a Fickian diffusion. All materials tested were shown to be active against pathogenic microorganisms. The mucoadhesiveness, bioadhesiveness, mechanical resistance, release kinetic, and antimicrobial activity make these biocomposites to be candidates as potential systems for controlled drug release
Scaffolds Based on Collagen, Hyaluronan and Sericin with Potential Applications as Controlled Drug Delivery System
International audienc
Development of Vaginal Carriers Based on Chitosan-Grafted-PNIPAAm for Progesterone Administration
Chitosan-based hydrogels possess numerous advantages, such as biocompatibility and non-toxicity, and it is considered a proper material to be used in biomedical and pharmaceutical applications. Vaginal administration of progesterone represents a viable alternative for maintaining pregnancy and reducing the risk of miscarriage and in supporting the corpus luteum during fertilization cycles. This study aimed to develop new formulations for vaginal administration of progesterone (PGT). A previously synthesized responsive chitosan-grafted-poly (N-isopropylacrylamide) (CS-g-PNIPAAm) was formulated in various compositions with polyvinyl alcohol (PVA) as external crosslinking agent to obtain pH- and temperature-dependent hydrogels; the hydrogels had the capacity to withstand shear forces encountered in the vagina due to its mechanism of swelling once in contact with vaginal fluids. Three different hydrogels based on grafted chitosan were analyzed via Fourier-transform infrared spectroscopy (FTIR), swelling tests, in vitro drug release, and bioadhesion properties by TA.XTplus texture analysis. A higher amount of PVA decreased the swelling and the bioadhesion capacities of the hydrogel. All hydrogels showed sensitivity to temperature and pH in terms of swelling and in vitro delivery characteristics. By loading progesterone, the studied hydrogels seemed to possess even higher sensitivity than drug–free matrices. The release profile of the active substance and the bioadhesion characteristics recommended the CS-g-PNIPAAm/PVA 80/20 +PGT (P1) hydrogel as a proper constituent for the vaginal formulation for progesterone administration
Poly(Acrylic Acid)–Poly(Ethylene Glycol) Nanoparticles Designed for Ophthalmic Drug Delivery
Poly(acrylic acid) (PAA) and poly(ethylene glycol) (PEG), four-arm, amine-terminated particles with nanometer size and spherical shape were obtained by the polymers cross-linking, via activation with 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride, in a w/o emulsion. The morphology and surface charge of the final particles are strongly dependent on the molar ratio of PAA–PEG and the PAA concentration. The physicochemical characteristics correlated with the drug-loading capacity, in vitro and ex vivo release kinetics of pilocarpine hydrochloride and biocompatibility results indicate that these nanoparticles exhibit the prerequisite behavior for use as carriers of ophthalmic drugs
Biomimetic Composites Based on Calcium Phosphates and Chitosan - Hyaluronic Acid with Potential Application in Bone Tissue Engineering
Magnetic Composite Scaffolds for Potential Applications in Radiochemotherapy of Malignant Bone Tumors
Background and objectives: Cancer is the second leading cause of death globally, an alarming but expected increase. In comparison to other types of cancer, malignant bone tumors are unusual and their treatment is a real challenge. This paper’s main purpose is the study of the potential application of composite scaffolds based on biopolymers and calcium phosphates with the inclusion of magnetic nanoparticles in combination therapy for malignant bone tumors. Materials and Methods: The first step was to investigate if X-rays could modify the scaffolds’ properties. In vitro degradation of the scaffolds exposed to X-rays was analyzed, as well as their interaction with phosphate buffer solutions and cells. The second step was to load an anti-tumoral drug (doxorubicin) and to study in vitro drug release and its interaction with cells. The chemical structure of the scaffolds and their morphology were studied. Results: Analyses showed that X-ray irradiation did not influence the scaffolds’ features. Doxorubicin release was gradual and its interaction with cells showed cytotoxic effects on cells after 72 h of direct contact. Conclusions: The obtained scaffolds could be considered in further studies regarding combination therapy for malignant bone tumors