RESUMO
Surgical sutures represent the gold standard for wound closure, however, their main purpose is still limited to a mechanical function rather than playing a bioactive role. Since oxygen and pro-regenerative growth factors have been broadly described as key players for the healing process, in this study we evaluated the feasibility of generating photosynthetic sutures that, in addition to mechanical fixation, could locally and stably release oxygen and recombinant human growth factors (VEGF, PDGF-BB, or SDF-1α) at the wound site. Here, photosynthetic genetically modified microalgae were seeded in commercially available sutures and their distribution and proliferation capacity was evaluated. Additionally, the mechanical properties of seeded sutures were compared to unseeded controls that showed no significant differences. Oxygen production, as well as recombinant growth factor release was quantified in vitro over time, and confirmed that photosynthetic sutures are indeed a feasible approach for the local delivery of bioactive molecules. Finally, photosynthetic sutures were tested in order to evaluate their resistance to mechanical stress and freezing. Significant stability was observed in both conditions, and the feasibility of their use in the clinical practice was therefore confirmed. Our results suggest that photosynthetic gene therapy could be used to produce a new generation of bioactive sutures with improved healing capacities. STATEMENT OF SIGNIFICANCE: Disruption of the vascular network is intrinsic to trauma and surgery, and consequently, wound healing is characterized by diminished levels of blood perfusion. Among all the blood components, oxygen and pro-regenerative growth factors have been broadly described as key players for the healing process. Therefore, in this study we evaluated the feasibility of generating photosynthetic sutures that, in addition to mechanical fixation, could locally and stably release oxygen and recombinant human growth factors at the wound site. This novel concept has never been explored before for this type of material and represents the first attempt to create a new generation of bioactive sutures with improved regenerative capabilities.
Assuntos
Portadores de Fármacos , Peptídeos e Proteínas de Sinalização Intercelular , Oxigênio , Suturas , Ferimentos e Lesões , Células 3T3 , Animais , Parede Celular/química , Chlamydomonas reinhardtii/química , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/farmacologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/química , Peptídeos e Proteínas de Sinalização Intercelular/farmacocinética , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Camundongos , Microalgas/química , Oxigênio/química , Oxigênio/farmacocinética , Oxigênio/farmacologia , Proteínas Recombinantes/química , Proteínas Recombinantes/farmacocinética , Proteínas Recombinantes/farmacologia , Ferimentos e Lesões/metabolismo , Ferimentos e Lesões/patologia , Ferimentos e Lesões/terapiaRESUMO
The use of artificial tissues in regenerative medicine is limited due to hypoxia. As a strategy to overcome this drawback, we have shown that photosynthetic biomaterials can produce and provide oxygen independently of blood perfusion by generating chimeric animal-plant tissues during dermal regeneration. In this work, we demonstrate the safety and efficacy of photosynthetic biomaterials in vivo after engraftment in a fully immunocompetent mouse skin defect model. Further, we show that it is also possible to genetically engineer such photosynthetic scaffolds to deliver other key molecules in addition to oxygen. As a proof-of-concept, biomaterials were loaded with gene modified microalgae expressing the angiogenic recombinant protein VEGF. Survival of the algae, growth factor delivery and regenerative potential were evaluated in vitro and in vivo. This work proposes the use of photosynthetic gene therapy in regenerative medicine and provides scientific evidence for the use of engineered microalgae as an alternative to deliver recombinant molecules for gene therapy.