Abstract
In the melt electrospinning technique, the polymer melt is stretched under high voltage and the cooled to form microfibers structures with a fibre diameter in the tens of micrometres range, ...although some studies have reported values ranging from hundreds of nanometres to hundreds of micrometres. In this respect, this technique has significance in the biomedical field, where tissue engineering scaffolds with bimodal (nano and micro) fibrous structures are preferred in regard to cell adhesion, spreading and infiltration to final tissue reconstruction. This paper gives a review of recently reported melt electrospinning devices, especially those based on the direct writing principle, and of their comparison with the new melt Spraybase electrospinning device. The Spraybase device provides high precision melt jet deposition into 2D and 3D programmed architectures, with versatile translation speeds of the collector plate in the X-Y and the melt head in the Z direction. The melt spun fibrous architectures are designed depending on the types of tissue cells used in scaffold development.
Limbal Stem Cell Deficiency (LSCD) is a very serious and painful disease that often results in impaired vision. Cultivation of limbal stem cells for clinical application is usually performed on ...carriers such as amniotic membrane or surgical fibrin gel. Transplantation of these grafts is associated with the risk of local postoperative infection that can destroy the graft and devoid therapeutic benefit. For this reason, electrospun scaffolds are good alternatives, as proven to mimic the natural cells surroundings, while their fabrication technique is versatile with regard to polymer functionalization and scaffolds architecture. This study considers the development of poly(ε-caprolactone) (PCL) immune-compatible and biodegradable electrospun scaffolds, comprising cefuroxime (CF) or titanium dioxide (TiO2) active components, that provide both bactericidal activity against eye infections and support of limbal stem cells growth in vitro. The PCL/CF scaffolds were prepared by blend electrospinning, while functionalization with the TiO2 particles was performed by ultrasonic post-processing treatment. The fabricated scaffolds were evaluated in regard to their physical structure, wetting ability, static and dynamic mechanical behaviour, antimicrobial efficiency and drug release, through scanning electron microscopy, water contact angle measurement, tensile testing and dynamic mechanical analysis, antimicrobial tests and UV-Vis spectroscopy, respectively. Human limbal stem cells, isolated from surgical remains of human cadaveric cornea, were cultured on the PCL/CF and PCL/TiO2 scaffolds and further identified through immunocytochemistry in terms of cell type thus were stained against p63 marker for limbal stem cells, a nuclear transcription factor and cytokeratin 3 (CK3), a corneal epithelial differentiation marker. The electrospun PCL/CF and PCL/TiO2 successfully supported the adhesion, proliferation and differentiation of the cultivated limbal cells and provided the antimicrobial effect against Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans.
Cells grown on bioactive matrices have immensely advanced many aspects of biomedical research related to drug delivery and tissue engineering. Our main objective was to perform simple evaluation of ...the structural and biotic qualities of cell scaffolds made of affordable biomaterials for liver cell line (HepG2) cultivation in vitro. In this work the electrospun matrix made of synthetic polyester poly(ε-caprolactone) (PCL) was compared with the natural protein-based extracellular matrix isolated from porcine liver (ECM). Mechanical and structural analysis showed that ECM was about 12 times less resistant to tensile stress while it had significantly larger pore size and twice smaller water contact angle than PCL. Bioactivity assessment included comparison of cell growth and transfection efficiency on cell-seeded scaffolds. Despite the differences in composition and structure between the two respective matrices, the rate of cell spreading and the percentage of transfected cells on both scaffolds were fairly comparable. These results suggest that in an attempt to produce simple, cell carrying structures that adequately simulate the natural scaffold, one can rely on PCL electrospun mats.
Personalizacija dimenzija i oblika obuće od iznimnog je značaja i u današnje vrijeme od strane interdisciplinarnih struka (medicinske, obućarske, ergonomske ...) priznata kao vitalno važna, glede toga ...jer pogrešno izvedena obuća neminovno rezultira s neželjenim patološkim stanjima stopala. Cilj ovog istraživanja bio je znanstveno utvrditi primjenu automatizirane 3D digitalizacije prostorne antropometrijske izmjere stopala u odnosu na učestalost pogrešno odabrane obuće na temelju tradicionalnih metoda izmjere i odabira. Među ispitanim entitetima, podjednako muškog i ženskog spola utvrđeno je da više od
dvije trećine osoba nosi obuću koja ergonomski nije odgovarala temeljnim antropometrijskim izmjerama obuće, kako u širini, tako ni u duljini njihovih stopala. Postoje medicinski dokazi da je nošenje neodgovarajuće obuće usko povezano s bolovima i ranama u stopalima, a trajnim nošenjem i patološkim promjenama stopala, kao primjerice deformacijom stopala i nožnih prstiju. Tradicionalne metode determiniranja morfologije stopala u svom opsegu uzimanja mjera nisu dovoljne da točno definiraju oblik i veličinu, za razliku od suvremenog pristupa uporabe 3D skenera i digitalnih metoda izmjera 3D
virtualnih modela, koji su u mogućnosti iznimno precizno i brzo personalizirati veliki broj antropometrijskih podataka morfologije stopala.
In this paper, the effect of different collector geometry on the PCL scaffold architecture and cell viability was investigated. PCL scaffolds with antibiotic Cefuroxim
®
, 15%wt. and 20%wt., were ...electrospun and characterized by ATR-FTIR, while thermal stability were observed by DSC and TG. PCL/15%CFU
®
scaffolds were electrospun on six 3D printed collectors, three ribbed and three mesh geometries, to produce the most favourable structure for cells adhesion and proliferation. SEM study and MTT assay revealed that collectors with the widest slot in both ribbed and mesh geometries exhibited the most favourable structure to enhance cells adhesion. In general, cells spreading on the surface and cells viability proved to be better for the ribbed collectors. The study showed that by controlling the collector geometry and the scaffold three-dimensional structure, it is possible to control cell attachment and differentiation and, consequently, to adjust them for the special tissue demands in the regeneration process.
Limbal stem cells (LSCs) are of paramount importance in corneal epithelial tissue repair. The cornea becomes opaque in case of limbal stem cell deficiency (LSCD), which may cause serious damage to ...the ocular visual function. There are many techniques to restore damaged epithelium, one of which is the transplantation of healthy cultured LSCs, usually onto a human amniotic membrane or onto bio-based engineered scaffolds in recent years. In this study, melt electrospun polylactic acid (PLA) was modified by silk fibroin or gelatin and further cultured with LSCs originating from three different donors. In terms of physicochemical properties, both modifications slightly increased PLA scaffold porosity (with a significantly larger pore area for the PLA/gelatin) and improved the scaffolds' swelling percentage, as well as their biodegradation rate. In terms of the scaffold application function, the aim was to detect/visualize whether LSCs adhered to the scaffolds and to further determine cell viability (total number), as well as to observe p63 and CK3 expressions in the LSCs. LSCs were attached to the surface of microfibers, showing flattened conformations or 3D spheres in the formation of colonies or agglomerations, respectively. All scaffolds showed the ability to bind the cells onto the surface of individual microfibers (PLA and PLA/gelatin), or in between the microfibers (PLA/silk fibroin), with the latter showing the most intense red fluorescence of the stained cells. All scaffolds proved to be biocompatible, while the PLA/silk fibroin scaffolds showed the highest 98% viability of 2.9 × 10
LSCs, with more than 98% of p63 and less than 20% of CK3 expressions in the LSCs, thus confirming the support of their growth, proliferation and corneal epithelial differentiation. The results show the potential of these bio-engineered scaffolds to be used as an alternative clinical approach.
Tkivno inženjerstvo dobra je alternativa za razvoj tkiva ili potencijalnih organa iz pacijentova vlastitog staničnog materijala, a kako bi se smanjio problem nedostatka organa za transplantaciju. ...Elektroispredeni materijali su dobri kandidati kod primjene u biomedicini tj. kao nosači za uzgoj tkivnih stanica. Kod regeneracije tkiva mogu dodatno prenositi lijekove kontrolirano prema terapiji. U ovom je radu istraživano kontrolirano otpuštanje antibiotika Cefuroxima (CFU) koji se upotrebljava u terapiji okularnog tkiva. Elektroispredeni su polikaprolaktonski nosači uz dodatak CFU-a u udjelima od 1, 2, 5 i 10 mas %. Uspješna kapsulacija antibiotika potvrđena je pojavom novih karakterističnih pikova u FTIR spektrima elektroispredenih mješavina. Dodatkom antibiotika i povećanjem njegove koncentracije dobivaju se vlakna homogenijeg izgleda s manjim brojem deformacija po duljini vlakna. UV-VIS spektrofotometrijom praćeno je vrijeme otpuštanja antibiotika iz elektroispredenih PCL/CFU nosača. Dobiveno je povećanje apsorbancije antibiotika s vremenom i porastom koncentracije lijeka u nosaču.
Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna .
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