ABSTRACT
In the last few decades, hydroxyapatite (HA) has become one of the most highly prized biominerals in the biomedical industry for orthopedic and dental applications. The focus of this research was to synthesize biomimetic HA from Tridax procumbens (TP) leaf extract and investigate their antibiofilm properties. The HA was made using the sol-gel method and the HA-TP biocomposite was made by precipitation method. The d.nm size of HA and HA-TP biocomposite was determined as 193.28 and 258.14 d.nm, respectively. The zeta potential of HA and HA-TP biocomposite was determined as ?21.2 and ?18.3 mV, respectively, and found highly stable. The FTIR study revealed that phytochemicals of TP were successfully impregnated into HA-TP biocomposite. The HA and HA-TP biocomposite were found spherical and agglomerated from SEM analysis. In HR-TEM analysis, the average diameter of the HA and HA-TP biocomposite were 16.57 – 64.22 nm and 51.71 – 138.68 nm, respectively. According to the EDX analysis, HA is primarily composed of calcium, oxygen, and phosphate, whereas, HA-TP biocomposite is primarily composed of calcium, phosphate, oxygen, and carbon. In the antioxidant assay, the IC50 value (concentration required to scavenge 50% of free radicals) of HA-TP biocomposite was determined as 156.69 ± 14.02 and 180.21 ± 12.84 µg/mL in DPPH and ABTS free radical scavenging assays, respectively. The MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) of as-synthesized HA-TP biocomposite against Staphylococcus aureus – ATCC 13565 and Escherichia coli – MTCC 41 were observed as 181.09 ± 21.47 and 317.30 ± 41.03, and 157.59 ± 32.18 and 264.03 ± 21.58 µg/mL, respectively. The as-synthesized HA-TP biocomposite has detrimentally affected the biofilm formation of both the tested bacteria S. aureus – ATCC 13565 and E. coli – MTCC 41. The study concluded that the as-synthesized HA-TP biocomposite could be highly helpful in the biomedical field for alleviating oxidative-stress-related disorders and inhibiting microbial biofilm formation.
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ABSTRACT Using the classic biotechnological methods, the dependence of A. vinelandii D-05 culture alginate production from the media carbon and nitrogen content was investigated. The maximal alginate production was observed during cultivation bacterium in the medium with 2 to 4% of sucrose, but the maximal growth was found in the medium with 4% glucose. It was found that for the alginate production the optimal nitrogen contents could take from 0.05% yeast extract (carbon: nitrogen ratio 168:1). For the first time we demonstrated possibility the A. vinelandii growth during the cultivation in a medium with molasses (a by-product of sugar production) and the significant polysaccharide production (16.6 g/l) was obtained. It was established, that A. vinelandii culture broth could be used as a biological binder for obtaining the biocomposite materials.
ABSTRACT
BACKGROUND: This study is performed to evaluate anchor-related outcomes and complications after arthroscopic rotator cuff repair using 30% β-tricalcium phosphate (β-TCP) with 70% poly lactic-co-glycolic acid (PLGA) biocomposite suture anchors. METHODS: A total of 78 patients (mean age, 61.3 ± 6.9 years) who underwent arthroscopic medium-to-large full-thickness rotator cuff tear repair were enrolled. The technique employed 30% β-TCP with 70% PLGA biocomposite suture anchors at the medial row (38 patients, Healix BRTM anchor [Healix group]; 40 patients, Fixone anchor B [Fixone group]). The radiologic outcomes (including perianchor cyst formation or bone substitution) and anatomical outcomes of the healing failure rate were evaluated using magnetic resonance imaging at least 6 months after surgery, the pain visual analogue scale at 3, 6 months, and final follow-up visit, and American Shoulder and Elbow Surgeons scores at least 1 year postoperatively. Anchor-related complications were also evaluated. RESULTS: The perianchor cyst formation incidence was similar for both groups (60.5%, Healix group; 60.0%, Fixone group; p=0.967), although severe perianchor cyst incidence was slightly lower in the Fixone group (15.0%) than in the Healix group (21.1%). There was no occurrence of anchor absorption and bone substitution. No differences were observed in the healing failure rate (13.2%, Healix group; 15.0%, Fixone group; p=0.815) and functional outcome between groups (all p>0.05). Anchor breakage occurred in 5 patients (2 Healix anchors and 3 Fixone anchors); however, there were no major anchor-related complications in either group. CONCLUSIONS: No differences were observed in the clinical outcomes of the Healix and Fixone groups, neither were there any accompanying major anchor-related complications.
Subject(s)
Humans , Absorption , Elbow , Follow-Up Studies , Incidence , Magnetic Resonance Imaging , Rotator Cuff , Shoulder , Surgeons , Suture Anchors , Sutures , TearsABSTRACT
La investigación se trata de la obtención de un biocompuesto a partir de una matriz cerámica y un polímero, con el fin de utilizarlo como relleno óseo. Se mezcló la matriz cerámica, fosfato tricálcico Ca (OH)2 y quitosana, polímero de origen natural. En el estudio se realizaron pruebas preliminares de mezclas para escoger 4 tipos de biocompuestos (BC1, BC2, BC3, BC4), con diferentes proporciones de los elementos de la matriz cerámica. Se trabajó en la preparación del biocompuesto con un pH entre 6,5 y 8,5 y un tiempo de secado entre 7 y 20 min. Se seleccionaron las mezclas óptimas para analizar sus propiedades mecánicas a partir de la prueba de la resistencia a la compresión. Se determinaron los valores de pH, los cuales estuvieron en un rango de 7,05 y 7,6. Igualmente se hallaron unos tiempos de secado que oscilaron entre 7 y 15 min, la pasta mantuvo una temperatura constante de 25 ºC y consistencia moldeable, condiciones que son apropiadas para su utilización como sustituto óseo. La muestra que obtuvo mejores propiedades en cuanto a pH, temperatura y tiempo de secado fue seleccionada para ser implantada en tibias de conejo para determinar la respuesta histológica después de 60 días...
The research deals with the development of a biocomposite from a ceramic matrix and a polymer with the purpose of using it as bone filler. A mixture was made of the ceramic matrix, tricalcium phosphate Ca (OH)2 and chitosan, a polymer of natural origin. The mixtures underwent preliminary testing to choose 4 types of biocomposites (BC1, BC2, BC3, BC4) with varying proportions of ceramic matrix elements. The biocomposite was prepared at a pH between 6.5 and 8.5. Drying time ranged between 7 and 20 minutes. Optimal samples were chosen and their mechanical properties analyzed by means of compression resistance testing. PH measurements showed values between 7.05 and 7.6, and drying times ranged between 7 and 15 minutes. The paste remained at a constant temperature of 25 ºC and maintained molding consistency. These properties are required for use as bone substitute. The sample exhibiting the best pH, temperature and drying time values was chosen for implantation in rabbit tibiae to verify the histological response after 60 days...
ABSTRACT
Objective To Investigate the toughness mechanism of the hierarchical and eximious micro-nanostructures from shankbone biocomposite. Methods The hierarchical micro-nanostructures of a mature shankbone were observed with a scanning electronic microscope and then to explore the toughness mechanism of this shankbone by the analyses on the models with hierarchical micro-nanostructures. Results The shankbone was made from a kind of biocomposite with hierarchical micro-nanostructures, consisting of hydroxyapatite and collagen protein matters. The micro-nanostructural model analyses at different scales indicated that the multilayer microstructure of the bone increased its fracture energy and the crossed microstructure of the hydroxyapatite fiber sheets as well as its long and thin shape size enhanced the maximum pullout energy of the fiber sheets. Conclusions The hierarchical and eximious micro-nanostructures in the bone endow the shankbone with high fracture toughness, and can be applied to the design of biomimetic composites.