1,721,113 research outputs found
Nanostructured coatings with bacteria-triggered antimicrobial response for medical devices
No full textBacterial colonization and biofilm formation on medical devices is one of the most pressing current healthcare issues, posing serious threats to patients health other than having a great economic impact on national healthcare systems. Smart and tailored biomaterials
for the fabrication of medical devices are needed to contrast this problem, in particular
the development of surface modification strategies, preventing bacteria adhesion and proliferation into mature biofilm. Layer-by-layer (LbL) assembly technique allows for easy, reproducible and specially designed surface modifications, providing the material with the desired antibiofilm activity.
More interestingly, LbL coatings can also display smart, stimuli-responsive features
to favour a controlled, on-demand antibacterial response which is triggered only when bacteria are present (self-defensive coatings)
Dispositivo protesico impiantabile e procedimento di solvent casting per la sua fabbricazione
No full textPoly(DL-lactide-co-ε-caprolactone) and poly(DL-lactide-co-glycolide) blends for biomedical application: Physical properties, cell compatibility, and in vitro degradation behavior
No full textPoly(DL-lactide-co-ε-caprolactone) (PLCL) and poly(DL-lactide-co-glycolide) (PLGA) blends of various compositions were prepared. Fractured sections of PLCL/PLGA blends did not evidence phase separation and blend glass transition temperatures suggested some degree of blend compatibility. The elastic modulus showed a negative deviation from the additive law of mixture. Superior biocompatibility in terms of fibroblast NIH 3T3 cell adhesion and proliferation, better mechanical properties, and a more homogeneous phase were obtained with PLCL/PLGA 25/75 blend. Rapid degradation of PLCL phase (4-8 weeks) in PLCL/PLGA 25/75 blend led to a porous structure, which makes it a potential candidate for drug delivery system
Gellan gum/tannic acid hydrogels for cartilage repair: the versatile role of tannic acid as green crosslinker conferring antibacterial and anti-inflammatory properties
No full text[EN] A novel hydrogel, containing two gellan gums with different acyl content crosslinked with tannic acid and magnesium ions, was proposed as cartilage substitute. In addition to crosslinking, tannic acid was employed as an anti-inflammatory and antioxidant compound. The analytical characterization of the hydrogel revealed that the interaction between carbohydrates and tannic acid consisted of hydrogen bonds. The hydrogel showed satisfactory mechanical performances (compressive Young's modulus up to 188 +/- 12 kPa, and strain at break up to 55.3 +/- 1.5 %). The biological results demonstrated that tannic acid-loaded hydrogels were cytocompatible and significantly enhanced the genetic expression of key chondrogenic markers (Collagen type 2 and SRY-Box Transcription Factor 9), showing up-regulation of similar to 30- and 14-fold under physiological conditions, and similar to 6- and 3-fold under pro-inflammatory conditions of oxidative stress, compared to the unloaded hydrogels. Moreover, the intrinsic ability of tannic acid to bind pro-inflammatory active species under oxidative stress imparted the scaffold with immunomodulatory properties, as shown by the upregulation of the anti-inflammatory genes Interlukin-10 and Interferon-gamma. Finally, tannic acid reported bactericidal and anti-biofilm activity, achieving a bacterial load reduction of over 90 % when hydrogels were infected with Staphylococcus aureus. Thus, this research highlights the multiple bioactivity of the gellan gum/tannic acid hydrogel for cartilage regeneration.Dr Stefano Todisco (DICATECh Department Politecnico di Bari, Bari, Italy) is greatly acknowledged for is precious collaboration in SS-NMR measurements. The authors acknowledge the support of the Department of Health Sciences (DiSS) of the Universita del Piemonte Orientale through the APC initiative.Busto, F.;Scalia, AC.;Gentile, Piergiorgio;Toniolo, S.;Cometa, S.;Liotino, S.;Cochis, A.... (2025). Gellan gum/tannic acid hydrogels for cartilage repair: the versatile role of tannic acid as green crosslinker conferring antibacterial and anti-inflammatory properties. Carbohydrate Polymer Technologies and Applications. 10. https://doi.org/10.1016/j.carpta.2025.100860S1
Optimizing nozzle design in extrusion-based 3D bioprinting to minimize mechanical stress and enhance cell viability
No full text[EN] Extrusion-based three-dimensional bioprinting is a widely used technique for fabricating cell-laden constructs in tissue engineering and regenerative medicine. However, the mechanical stresses experienced by cells during the printing process can negatively affect their viability. This study examines the influence of nozzle geometry-specifically contraction angleand outlet diameter-on stress distribution and its effects on cell survival. Through a combination of experimental analysis and theoretical modeling, the impacts of nozzle design on the balance between shear and extensional stresses during bioprinting are explored. The findings highlight the importance of optimizing nozzle parameters to minimize mechanical damage and enhance post-printing cell viability. The proposed model provides a framework for guiding nozzle design, offering insights into the development of customized bioprinting strategies that enhance construct fidelity and biological functionality. These results contribute to advancing bioprinting techniques for applications in tissue engineering and regenerative medicine.Lombardi, L.;Annachiara Scalzone;Ausilio, C.;Gentile, Piergiorgio;Tammaro, D. (2025). Optimizing nozzle design in extrusion-based 3D bioprinting to minimize mechanical stress and enhance cell viability. International Journal of Bioprinting. 11(4):315-327. https://doi.org/10.36922/IJB025190182S31532711
Collagen for bone tissue regeneration
No full textIn the last decades, increased knowledge about the organization, structure and properties of collagen (particularly concerning interactions between cells and collagen-based materials) has inspired scientists and engineers to design innovative collagen-based biomaterials and to develop novel tissue-engineering products. The design of resorbable collagen-based medical implants requires understanding the tissue/organ anatomy and biological function as well as the role of collagen's physicochemical properties and structure in tissue/organ regeneration. Bone is a complex tissue that plays a critical role in diverse metabolic processes mediated by calcium delivery as well as in hematopoiesis whilst maintaining skeleton strength. A wide variety of collagen-based scaffolds have been proposed for different tissue engineering applications. These scaffolds are designed to promote a biological response, such as cell interaction, and to work as artificial biomimetic extracellular matrices that guide tissue regeneration. This paper critically reviews the current understanding of the complex hierarchical structure and properties of native collagen molecules, and describes the scientific challenge of manufacturing collagen-based materials with suitable properties and shapes for specific biomedical applications, with special emphasis on bone tissue engineering. The analysis of the state of the art in the field reveals the presence of innovative techniques for scaffold and material manufacturing that are currently opening the way to the preparation of biomimetic substrates that modulate cell interaction for improved substitution, restoration, retention or enhancement of bone tissue functio
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