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| Author(s): |
Jonathas Queiroz Ribeiro Moraes
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Carlos. |
| Institution: | Universidade de São Paulo (USP). Instituto de Física de São Carlos (IFSC/BT) |
| Defense date: | 2023-05-29 |
| Examining board members: |
Cleber Renato Mendonça;
Juliana Mara Pinto de Almeida;
Fabio Simoes de Vicente
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| Advisor: | Cleber Renato Mendonça |
| Abstract | |
Probiotics are microorganisms that bring benefits to their host and may have positive immunologic effects by stimulating the increase of beneficial bacteria of the gastrointestinal microbiota. Some studies have been showing that specific probiotic cultures can lessen symptoms of medical conditions such as Alzheimers disease, reduce cariogenic action, and control various biomarkers in women in the first half of pregnancy diabetes. Therefore, it is important to determine fundamental aspects about the formation of probiotic biofilms, in order to create more efficient delivery mechanisms in pharmaceutical and food applications. Hence, we aim to fabricate biocompatible tridimensional platforms using the two-photon polymerization (2PP) technique in order to study the growth of biological films of Lactobacillus sp. and Bifidobacterium sp., bacteria largely utilized in commercial probiotics. The microstructures were made of an acrylic resin composed of SR368, SR399 and SR499 monomers and the photoinitiator Irgacure TPO-L, sensitized by ultra-short laser pulses in order to promote the polymerization of acrylic monomers. In this work, a Ti:sapphire laser system centered at 790 nm, with full width at half maximum around 50 nm, 250 mW medium power, 100 fs pulses and a 86 MHz repetition rate was applied. Once the structures were fabricated, their biocompatibility was first studied with Escherichia coli fist, characterizing the biofilm development only afterwards. Biocompatible structures were fabricated, showcasing that probiotic growth in such framework accelerates bacterial development. Furthermore, bacteria lean to originate the formation of aggregates in partially open environments, in which nutrient flux in allowed, opposed to closed environments that are susceptible to population saturation. Also, a new behavior is shown, in which the bacteria tend to agglomerate forming a structural connection between the walls of the structure, in the likeness of a curtain. (AU) | |
| FAPESP's process: | 20/15736-6 - Fabrication of 3D microenvironments for the development of microorganisms |
| Grantee: | Jonathas Queiroz Ribeiro Moraes |
| Support Opportunities: | Scholarships in Brazil - Master |