Kesan Triali Isosianurat (TIAC) terhadap sifat tegangan filem Poly L-Laktid Asid (PLLA) yang diiradiasi gamma dan alur elektron

PLLA merupakan biodegrasi polimer yang mempunyai aplikasi yang meluas dalam pelbagai bidang industri dan perubatan. Dalam kajian ini, PLLA telah dicampurkan dengan triali isosianurat (TIAC) antara 1 hingga 6 v/v% bagi melihat perubahan sifat tegangan dan terikan filem PLLA. TIAC biasanya digunakan sebagai agen taut silang dan keplastikan untuk mengubah sifat polimer. Campuran PLLA-TIAC telah diiradiasi pada 10 kGy di bawah alur elektron (EB) dan gamma (γ). Keputusan menunjukkan kekuatan tegangan (tegasan maksimum) menurun dengan peningkatan kandungan TIAC di dalam PLLA tetapi meningkat sedikit pada 4 v/v% TIAC bagi PLLA iradiasi dan tanpa iradiasi. Manakala nilai terikan didapati meningkat pada TIAC 2 v/v% dan menurun apabila TIAC ditambah melebihi 2% v/v% terutamanya bagi PLLA yang diiradiasikan. Daripada keputusan DSC terdapat perubahan pada suhu peralihan kaca, Tg, suhu penghabluran sejuk, Tc, entalpi penghabluran sejuk, Hc dan suhu peleburan, Tm menunjukkan berlaku perubahan pergerakan rantaian PLLA dan fasa penghabluran dengan kehadiran TIAC dan sinaran mengion di dalam PLLA. Perubahan pada puncak penyerapan spektra infra merah jelmaan fourier (FTIR) menunjukkan berlaku penggantian atau kemasukkan molekul TIAC ke dalam rantian PLLA

Fabrication and characterisation of recycled polyethylene terephthalate/graphene oxide nanofibres as a potential adsorbent for methylene blue

Polymeric nanofibres can be good dye adsorbents as they have large surface areas, good connectivity, and tunable wettability. In this study, recycled polyethylene terephthalate (rPET) nanofibres loaded with graphene oxide (GO) in various amounts (0 - 1.5 v/v%) were fabricated using the electrospinning technique. GO is a carbonaceous material that exhibits a large specific area and contains an oxygenous functional group that significantly enhances the performance of electrospun nanofibres. Scanning electron microscopy images showed that rPET/GO had smooth fibres with diameters as low as 118 ± 56 nm. Fourier-Transform Infrared Spectroscopy (FTIR) confirmed GO had been well incorporated in the rPET nanofibres. The use of GO as a filler increased the tensile strength to 32.84 ± 0.33 MPa, and thus enhanced the mechanical properties of the polymeric nanofibres. The adsorption capacity of the rPET/GO nanofibres for methylene blue (MB) was evaluated, and rPET nanofibres loaded with GO showed better adsorption compared with pure rPET nanofibres. From this study, rPET/GO nanofibres show good potential as adsorbents for the treatment of dyes in wastewater

Kesan kandungan fosfat berbeza terhadap pembentukan morfologi permukaan, penghabluran, fasa, ikatan kimia dan kekuatan mampatan bio-kaca sol-gel tersinter

Kajian ini bertujuan untuk mengkaji kesan kandungan fosfat berbeza (X = 10, 15 dan 20% mol) terhadap pembentukan morfologi permukaan, ikatan kimia, penghabluran, fasa dan kekuatan mampatan kaca sol-gel tersinter. Serbuk kaca gel dengan komposisi 50SiO2.(50-X).CaO.XP2O5 (dalam peratusan mol) disediakan melalui kaedah sol-gel, dimampat membentuk pelet dan disinter pada suhu 1200°C selama 3 jam. Didapati bahawa dengan peningkatan kandungan fosfat, mikrostruktur kaca tersinter yang lebih padat terhasil disebabkan peningkatan pemadatan jasad, pengurangan keliangan ketara dan pembentukan butiran dan sempadan butiran berhablur yang lebih besar. Peningkatan sebanyak 20% mol kandungan fosfat meningkatkan vitrifikasi (fasa kekaca) pada permukaan kaca tersinter yang mana meningkatkan pemadatan jasad kepada 83.56%, kekuatan mampatan pada 113 MPa dan penurunan peratusan penghabluran pada sekitar 66%. Analisis EDS menunjukkan peningkatan kandungan fosfat menyebabkan peningkatan unsur Si-O pada fasa amorfus dan unsur P-O pada fasa berhablur. Analisis FTIR menunjukkan berlaku pemisahan fasa kaya fosfat dan fasa kaya silikat dan pada masa sama meningkatkan rangkaian tetrahedra silikat (Si-O-Si) dan fosfat (P-O-P) kaca tersinter. Peningkatan kandungan fosfat meningkatkan kumpulan berfungsi berkaitan fosfat hablur dan mengurangkan kumpulan berfungsi berkaitan silikat hablur. Ini menyebabkan peningkatan pembentukan fasa silikokarnotit, Ca5 (PO4)2 (SiO4) dalam matriks kaca tersinter dengan peningkatan kandungan fosfat yang ditunjukkan melalui analisis XRD

Electron-Beam Irradiation of the PLLA/CMS/beta-TCP Composite Nanofibers Obtained by Electrospinning

Nanofibrous materials produced by electrospinning processes have potential advantages in tissue engineering because of their biocompatibility, biodegradability, biomimetic architecture, and excellent mechanical properties. The aim of the current work is to study the influence of the electron beam on the poly L-lactide acid/ carboxy-methyl starch/beta-tricalcium phosphate (PLLA/CMS/beta-TCP) composite nanofibers for potential applications as bone-tissue scaffolds. The composite nanofibers were prepared by electrospinning in the combination of 5%v/vcarboxy-methyl starch (CMS) and 0.25 wt% of beta-TCP with the PLLA as a matrix component. The composites nanofibers were exposed under 5, 30, and 100 kGy of irradiation dose. The electron-beam irradiation showed no morphological damage to the fibers, and slight reduction in the water-contact angle and mechanical strength at the higher-irradiation doses. The chain scission was found to be a dominant effect; the higher doses of electron-beam irradiation thus increased the in vitro degradation rate of the composite nanofibers. The chemical interaction due to irradiation was indicated by the Fourier transform infrared (FTIR) spectrum and thermal behavior was investigated by a differential scanning calorimeter (DSC). The results showed that the electron-beam-induced poly L-lactide acid/carboxy-methyl starch/beta-tricalcium phosphate (PLLA/CMS/beta-TCP) composite nanofibers may have great potential for bone-tissue engineering

Decellularized and genipin crosslinked human umbilical cord artery and vein for potential use as peripheral nerve conduit

Critical gap peripheral nerve injury, commonly caused by motor vehicle accidents, results in dysfunctional nerve and impaired body function. Our study aims to develop a conduit from decellularized and genipin crosslinked human umbilical cord artery and vein for future use in critical nerve gap injury treatments. Human umbilical cord arteries (HUCA) and veins (HUCV) were divided into native (nHUCA and nHUCV), decellularized (dHUCA and dHUCV) and genipin-crosslinked (clHUCA and clHUCV) groups. Both the decellularized and crosslinked groups were decellularized, and subsequently, the clHUCA and clHUCV groups were crosslinked with 0.1%, 0.4% and 0.7% (w/v) genipin. The HUCA and HUCV were then studied for decellularization efficiency, crosslinking index, biodegradation, swelling ratio, ultrastructure analysis, flexibility and mechanical strength. In addition, mesenchymal stem cells isolated from Wharton’s jelly were seeded into HUCA and HUCV for biocompatibility studies. The degradation test showed that nHUCV and dHUCV degraded at day 7 compared to other groups that did not show any degradation even after 21 days. Biocompatibility studies showed that the conduits crosslinked with 0.4% (w/v) genipin were successfully seeded and was having the most amount of seeded cells. In conclusion, the decellularization and genipin crosslinking of human umbilical cord artery and vein enabled successful in fabrication of conduit with suitable properties such as reduced swelling, flexibility, porosity and mechanical strength, with potential in tissue engineering applications

Electron-Beam Irradiation of the PLLA/CMS/β-TCP Composite Nanofibers Obtained by Electrospinning

Nanofibrous materials produced by electrospinning processes have potential advantages in tissue engineering because of their biocompatibility, biodegradability, biomimetic architecture, and excellent mechanical properties. The aim of the current work is to study the influence of the electron beam on the poly L-lactide acid/ carboxy-methyl starch/β-tricalcium phosphate (PLLA/CMS/β-TCP) composite nanofibers for potential applications as bone-tissue scaffolds. The composite nanofibers were prepared by electrospinning in the combination of 5% v/v carboxy-methyl starch (CMS) and 0.25 wt% of β-TCP with the PLLA as a matrix component. The composites nanofibers were exposed under 5, 30, and 100 kGy of irradiation dose. The electron-beam irradiation showed no morphological damage to the fibers, and slight reduction in the water-contact angle and mechanical strength at the higher-irradiation doses. The chain scission was found to be a dominant effect; the higher doses of electron-beam irradiation thus increased the in vitro degradation rate of the composite nanofibers. The chemical interaction due to irradiation was indicated by the Fourier transform infrared (FTIR) spectrum and thermal behavior was investigated by a differential scanning calorimeter (DSC). The results showed that the electron-beam-induced poly L-lactide acid/carboxy-methyl starch/β-tricalcium phosphate (PLLA/CMS/β-TCP) composite nanofibers may have great potential for bone-tissue engineering

Fabrication and Characterization of Carboxymethyl Starch/Poly(l-Lactide) Acid/beta-Tricalcium Phosphate Composite Nanofibers via Electrospinning

A natural polymer of carboxymethyl starch (CMS) was used in combination with the inorganic mineral of beta-Tricalcium Phosphate (beta-TCP) and Poly L-lactide (PLLA) to prepare composite nanofibers with the potential to be used as a biomedical membrane. beta-TCP contents varied in the range of 0.25% to 1% in the composition of PLLA and CMS. A mixed composition of these organic and inorganic materials was electro-spun to produce composite nanofibers. Morphological investigation indicated that smooth and uniform nanofibers could be produced via this technique. The average of the nanofiber diameters was slightly increased from 190 to 265 nm with the beta-TCP content but some agglomeration of particles began to impede in the fiber at a higher content of beta-TCP. It was observed that the fibers were damaged at a higher content of beta-TCP nanoparticles. With the presence of higher beta-TCP, the wettability of the PLLA was also improved, as indicated by the water contact angle measurement from 127.3 degrees to 118 degrees. The crystallization in the composite decreased, as shown in the changes in glass transition (T-g) and melting temperature (T-m) by differential scanning calorimeter (DSC) and X-ray diffraction analysis. Increases in beta-TCP contributed to weaker mechanical strength, from 8.5 to 5.7 MPa, due to imperfect fiber structure

Electrospun Sulfonatocalix[4]arene Loaded Blended Nanofibers: Process Optimization and In Vitro Studies

In the past decade, electrospun nanofibers made of biodegradable polymers have been used for different biomedical applications due to their flexible features in terms of surface area to volume ratio, pores, and fiber size, as well as their highly tunable surface properties. Recently, interest is growing in the use of supramolecular structures in combination with electrospun nanofibers for the fabrication of bioactive platforms with improved in vitro responses, to be used for innovative therapeutic treatments. Herein, sulfonatocalix[4]arene (SCX4) was synthesized from p-tert-butyl-calix[4]arene and embedded in electrospun nanofibers made of polycaprolactone (PCL) and gelatin (GEL). The supramolecular structure of SCX4 and its efficient entrapment into electrospun fibers was confirmed by NMR spectroscopy and FTIR analysis, respectively. SEM analysis supported via image analysis enabled the investigation of the fiber morphology at the sub-micrometric scale, showing a drastic reduction in fiber diameters in the presence of SCX4: 267 ± 14 nm (without SCX) to 115 ± 5 nm (3% SCX4). Moreover, it was demonstrated that SCX4 significantly contributes to the hydrophilic properties of the fiber surface, as was confirmed by the reduction in contact angles from 54 ± 1.4° to 31 ± 5.5° as the SCX4 amount increased, while no effects on thermal stability were recognized, as was confirmed by TGA analyses. In vitro tests also confirmed that SCX4 is not cytotoxic, but plays a supporting role in L929 interactions, as was validated by the cell viability of PGC15% after 7 days, with respect to the control. These preliminary but promising data suggest their use for the fabrication of innovative platforms able to bind SCX4 to bioactive compounds and molecules for different therapeutic applications, from molecular recognition to controlled drug delivery