Papers by Keyword: Collagen

Abstract: This work employed biocompatible and antibacterial materials to coat a commercial pure titanium (Cp-Ti) substrate for orthopedic implants applications. Three sorts of coatings were utilized using the electrophoretic deposition (EPD) technique: collagen, yttria-partially stabilized zirconia (YPSZ), and a composite of collagen/YPSZ (denoted as CZ). Surface microstructure before and after coating was examined using scanning electron microscopy (SEM). Results presented that homogeneous and uniform coating layers were successfully deposited on all samples’ surface. A relatively low pores density was observed in the surface microstructure of composite-coated sample (CZ). The chemical composition of coatings was evaluated via energy-dispersive X-ray spectroscopy (EDX), confirming that all spectra matched those of standard materials, with no signs of contaminations. Adhesion strength of coatings was evaluated using a tape test. CZ-coated sample exhibited the smallest removal area at 11.81%, demonstrating superior adhesion strength. Wettability tests were conducted on the Cp-Ti substrate before and after coating. The results showed that the application of the collagen/YPSZ composite coatings significantly enhanced surface wettability by diminishing the contact angle, making the samples surface more hydrophilic. Post-deposition antibacterial activity was estimated against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) pathogenic bacteria. All coated samples demonstrated improved antibacterial performance compared to the uncoated Cp-Ti, with the CZ-coated sample exhibiting the largest inhibition zone of 32 mm and 37 mm against both E. coli and S.aureus bacteria respectively.

Abstract: Polyvinyl alcohol (PVA) is a non-toxic, thermoplastic polymer that is completely biodegradable. So it is based on many composite materials for biomedical applications. In this study, various specimens were prepared by solvent casting method and then tested by tensile, FTIR, contact angle, SEM, antibacterial and cytotoxicity test. The results obtained showed the tensile strength decreased with the addition of PEG and then tended to improve after the addition of collagen and nano-titanium oxide. The wettability test shows the prepared specimens changed from hydrophobic to hydrophilic properties. The biological properties explained that the prepared composite had a better antibacterial effect and none of the samples had a toxic effect.

Abstract: Due to the fact that mechanical properties in macroscale cannot respond to that of cell wall features, it has become important to investigate nanomechanical characteristics of scaffold materials and make suitable modifications if needed. Conventional methods of mechanical testing cannot characterize the spatial distribution of material, with non-uniform stiffness, at nanoscale. One of the important methods of nanoscale testing is the force mapping using the atomic force microscope. In the present study, A comprehensive approach was developed to determine and characterize surface distribution of elastic modulus for soft biomaterials at nanoscale. Elastic modulus has been determined for collagen fibers, modified with different percentage of bio-glass nonoparticles, 0%, 30% and 60%, by applying tiny forces (1 nN). The experiments are carried out in phosphate buffer saline (PBS) pH ~ 7, to mimic the physiological environment. The scanning was performed at two different spots for each sample and three different scan sizes to investigate the large scale and short scale heterogeneity, respectively. Deep-lying structures have been sensed by varying applied load (2 nN). Our results are in agreement with previous reports. The results show increasing elasticity with increase of bioglass in collagen samples. Yet adding more bioglass decreases the stiffness of collagen fibers to the point where they become difficult to handle. Samples appear to be strongly heterogeneous with increasing the scan size. The depth sensing measurements manifest higher elasticity which reflects the lower degree of freedom in the deep-lying structures.

Abstract: Collagen has been widely used in biomedical applications, mainly to develop structures (cell scaffolds) that allow cell growth and differentiation processes. This biomolecule is also used in cosmetics because it is an essential ingredient of certain makeup and in pharmaceutics for bandages to treat wounds and burns. However, the use of collagen has been limited by the ethical and moral implications of the (typically animal) sources from which it is extracted. Therefore, alternative, more environmentally friendly sources should be found to obtain collagen. Extracting collagen from fishing industry waste (such as scales, bones, and fish skin) has been presented as an advantageous alternative to obtain this biomaterial, which has also shown promising results due to its biocompatibility with human structures (organs and tissues). The characteristics of this molecule and other sources from which it can be obtained should be further studied.

Abstract: In an effort to produce ideal wound dressing, gellan gum/collagen hydrogel films containing different concentrations of gatifloxacin were prepared via evaporative casting method. The films were examined in terms of physical appearances, water uptake and water vapour transmission rate (WVTR). All the films showed good physical appearances. Swelling percentages of the films were decreased, whereas WVTR values were increased as the addition of gatifloxacin was increased. Swelling percentage of gellan gum/collagen film with the lowest percentage of gatifloxacin (GG/C-GAT01) has the highest swelling ratio (2057%). Meanwhile, the WVTR value of GG/C-GAT1 has the highest WVTR value among all films which is 1245 g m^-2 day^-1. The formulation of GG/C films with the addition of gatifloxacin with good water absorbance and acceptable WVTRs value offered promising materials to be applied as wound dressing materials.

Abstract: Smart thermosensitive polymer such as poly (N-isopropyl acrylamide) (PNIPAM) and dominant fibrous protein of connective tissue such as collagen (CLG) possess great potential in biomedical and tissue engineering applications. The objectives of current work aim to explore potential of PNIPAM and collagen by (i) establish a stable procedure to extract collagen from fresh water Tilapia fish scale (TFS) and (ii) fabricate PNIPAM and hybrid PNIPAM-CLG nanofibrous scaffolds through electrospinning technique and investigate their material-process-structure behaviour. Type I collagen was derived through acid hydrolysis of TFS. Electrospinning of PNIPAM was carried out with 16, 18 and 20 wt% PNIPAM concentration in methanol (MeOH) while PNIPAM-CLG was prepared through blending measured quantity of PNIPAM dissolved in water with collagen dissolved in acetic acid. Material properties, viscosity, morphology and thermo-physical behaviors of the derived collagen, electrospun PNIPAM and PNIPAM-CLG scaffolds were characterized. Results from SDS-PAGE and FTIR confirmed that the isolated TFS collagen is of type I. EDX revealed that demineralization eliminated the aluminium, magnesium, silicon and phosphorus while significantly reduced the sulfur elements from raw TFS. SEM observation of the collagen morphology shown a fluffy and fibrillary lamellae structure. Electrospun scaffolds were successfully fabricated with 16 and 18 wt% PNIPAM in MeOH. Both homogeneity and average fibre diameter (D_avg) were greater in the 18 wt% PNIPAM scaffold, in which the D_avg for 16 and 18 wt% were ~110 and ~131.7 nm respectively. However, PNIPAM at 20 wt% failed to be electrospun owing to its excessively high viscosity. On the other hand, SEM observation revealed that the electrospun hybrid PNIPAM-CLG scaffold has D_avg of ~105.5 nm amid the presence of numerous elongated beads.

Abstract: Structural and mechanical features of collagen-containing raw materials and biomaterials that can be used as coatings based on biopolymers are presented. Studies reveal the presence of materials with targeted texture, rheological properties; chemical composition and biocompatibility. In particular, for mycelial fungi.

Abstract: Synthesis of porous hydroxyapatite-collagen composites for bone implant applications has been carried out. Hydroxyapatite synthesized from coral by the precipitation method, while Collagen synthesized from chicken claws. Collagen formation was carried out by freeze-dry technique with variations in freezing time of 2, 4 and 6 hours at -80 ° C. The next process was by drying in a lyophilizer. Characterization of samples was carried out using Fourier Transform Infra Red (FTIR), Scanning Electron Microscopy (SEM), compressive strength test and cytotoxicity test with Microtetrazolium (MTT) assay. FTIR results proved that collagen uptake and hydroxyapatite combine chemically. This is indicated by the absorption of functional groups that did not coincide between collagen and hydroxyapatite functional groups with composites. SEM observations showed that the largest pore size was obtained at freezing for 2 hours which was 774 μm and the smallest in freezing for 6 hours was 640 μm. This pore size was an important parameter of the bone implant because it played a role in the osteoinductive process. The composite compressive strength test results for freezing 2 hours, 4 hours and 6 hours respectively was 737 KPa, 842 KPa and 707.7 KPa. The results of the cytotoxicity test with MTT showed the percentage of cell viability above 100%. This means that the Hydroxyapatite-collagen composite is non-toxic. So, the sample formed has qualified as a bone implant candidate.

Abstract: Calcium phosphate biocomposites are candidate materials for bone tissue engineering due to their conductivity and biocompatibility. Calcium phosphate could be grown on collagen by precipitation method in long reaction time. Microwave irradiation is rapid method to assist precipitation by reducing reaction time. In order to study carbonated calcium phosphate precipitation on collagen and investigate the influence of microwave irradiation time, the carbonated calcium phosphate has been grown on collagen by microwave assisted precipitation method. The collagen sheets were soaked in carbonated calcium phosphate suspension prepared by using Ca(NO₃)₂.4H₂O, (NH₄)₂HPO₄, and NaHCO₃ as starting materials, then microwave irradiated at 270 Watt for 2 minutes, 8 minutes, and 16 minutes. X-ray powder diffraction (XRD) pattern shows the transformation of dicalcium phosphate dyhydrate to apatite crystal structure. Increase in irradiation time had increased crystallinity of carbonate apatite phase. FTIR spectrum had confirmed presence of collagen, phosphate, and carbonate functional group. Scanning electron micrograph showed the presence of collagen with pore, and the carbonated calcium phosphate could attach and be deposited onto collagen.

Abstract: The number of blindness is tend to be increased year by year. One of the blindness cause is cornea ulcer.The cause of cornea ulcer is bacteria, fungi, and herpes simplex virus. Cornea transplantation is the only treatment which could widely accepted for blindness. Transplant by donor network becomes the only treatment that is acceptable on a large for blindness. However, treatment donor transplants have many shortcomings in complications post surgery such as host response, donor limitations, incompatibility and the length of time healing. As technology develops, there are many corneal substitutes based on natural ingredients derived from collagen or their derivatives because they promise better properties in biocompatibility. The aim of research are to conduct the synthesis and characterization of collagen- chitosan- glycerol - HPMC as artificial cornea such functional cluster test, cytotoxycity test, morphological test and antibacterial test. Based on functional cluster test, there are functional groups of all components of composite materials. While from cytotoxicity test, all samples have a percentage of living cells above 85%. The morphology test is showed that the pore size of sample B with composition collagen-chitosan-glycerol-HPMC is in accordance with the standard pore size for keratoprothesis. Sample A (collagen-chitosan-glycerol) and sample B (collagen-chitosan-glycerol-HPMC) have strong antibacterial properties.Biocomposite of collagen-chitosan-glycerol could be considered as artificial cornea due to the proximity with the corneal characteristics.