Browsing by Author "Miranda, Miguel"

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    Development of a photosynthetic hydrogel as potential wound dressing for the local delivery of oxygen and bioactive molecules.
    (2022) Corrales-Orovio, Rocío; Carvajal, Felipe; Holmes, Christopher; Miranda, Miguel; González-Itier, Sergio; Cárdenas, Camila; Vera, Constanza; Schenck, Thilo; Egaña, José Tomás
    The development of biomaterials to improve wound healing is a critical clinical challenge and an active field of research. As it is well described that oxygen plays a critical role in almost each step of the wound healing process, in this work, an oxygen producing photosynthetic biomaterial was generated, characterized, and further modified to additionally release other bioactive molecules. Here, alginate hydrogels were loaded with the photosynthetic microalgae Chlamydomonas reinhardtii, showing high integration as well as immediate oxygen release upon illumination. Moreover, the photosynthetic hydrogel showed high biocompatibility in vitro and in vivo, and the capacity to sustain the metabolic oxygen requirements of zebrafish larvae and skin explants. In addition, the photosynthetic dressings were evaluated in 20 healthy human volunteers following the ISO-10993-10-2010 showing no skin irritation, mechanical stability of the dressings, and survival of the photosynthetic microalgae. Finally, hydrogels were also loaded with genetically engineered microalgae to release human VEGF, or pre-loaded with antibiotics, showing sustained release of both bioactive molecules. Overall, this work shows that photosynthetic hydrogels represent a feasible approach for the local delivery of oxygen and other bioactive molecules to promote wound healing.
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    Oxygenation by Intravascular Photosynthesis Reduces Kidney Damage During ex Vivo Preservation
    (2024) Veloso-Gimenez, Valentina; Cardenas-Calderon, Camila; Castillo, Valentina; Carvajal, Felipe; Gallardo-Aguero, Daniela; Gonzalez-Itier, Sergio; Corrales-Orovio, Rocio; Becerra, Daniela; Miranda, Miguel; Rebolledo, Rolando; San Martin, Sebastian; Boric, Mauricio P.; Egana, Jose Tomas
    Several clinical issues are associated with reduced oxygen delivery to tissues due to impaired vascular perfusion; moreover, organs procured for transplantation are subjected to severe hypoxia during preservation. Consequently, alternative tissue oxygenation is an active field in biomedical research where several innovative approaches have been recently proposed. Among these, intravascular photosynthesis represents a promising approach as it relies on the intrinsic capacity of certain microorganisms to produce oxygen upon illumination. In this context, this work aims at the development of photosynthetic perfusable solutions that could be applied to preserve organs for transplantation purposes. Our findings demonstrate that a biocompatible physiological solution containing the photosynthetic microalgae Chlamydomonas reinhardtii can fulfill the metabolic oxygen demand of rat kidney slices in vitro. Furthermore, intravascular administration of this solution does not induce tissue damage in the rat kidneys. Moreover, kidney slices obtained from these algae-perfused organs exhibited significantly improved preservation after 24 h of incubation in hypoxia while exposed to light, resulting in reduced tissue damage and enhanced metabolic status. Overall, the results presented here contribute to the development of alternative strategies for tissue oxygenation, supporting the use of perfusable photosynthetic solutions for organ preservation in transplantation.
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    Plants as a cost‐effective source for customizable photosynthetic wound dressings: A proof of concept study
    (2024) González Itier, Sergio Andrés; Miranda, Miguel; Corrales‐Orovio, Rocío; Vera, Constanza; Veloso‐Giménez, Valentina; Cárdenas Calderón, Camila Valentina; Egaña, José Tomás
    Oxygen is essential for tissue regeneration, playing a crucial role in several processes, including cell metabolism and immune response. Therefore, the delivery of oxygen to wounds is an active field of research, and recent studies have highlighted the potential use of photosynthetic biomaterials as alternative oxygenation approach. However, while plants have traditionally been used to enhance tissue regeneration, their potential to produce and deliver local oxygen to wounds has not yet been explored. Hence, in this work we studied the oxygen-releasing capacity of Marchantia polymorpha explants, showing their capacity to release oxygen under different illumination settings and temperatures. Moreover, co-culture experiments revealed that the presence of these explants had no adverse effects on the viability and morphology of fibroblasts in vitro, nor on the viability of zebrafish larvae in vivo. Furthermore, oxygraphy assays demonstrate that these explants could fulfill the oxygen metabolic requirements of zebrafish larvae and freshly isolated skin biopsies ex vivo. Finally, the biocompatibility of explants was confirmed through a human skin irritation test conducted in healthy volunteers following the ISO-10993-10-2010. This proof-of-concept study provides valuable scientific insights, proposing the potential use of freshly isolated plants as biocompatible low-cost oxygen delivery systems for wound healing and tissue regeneration.