Generation of a novel human dermal substitute functionalized with antibiotic-loaded nanostructured lipid carriers (NLCs) with antimicrobial properties for tissue engineering

Jesús Chato-Astrain,Claudia Vairo,Óscar-Darío García-García,Fernando Campos,María Villar-Vidal,Roke-Iñaki Oruezabal,Silvia Villullas,Miguel Alaminos,Ángela Ponce-Polo,David Sánchez-Porras,Ingrid Garzón,Víctor Carriel,Fabiola Bermejo-Casares,Isabel Chato-Astrain,Garazi Gainza

doi:10.1186/s12951-020-00732-0

Abstract

BackgroundTreatment of patients affected by severe burns is challenging, especially due to the high risk of Pseudomonas infection. In the present work, we have generated a novel model of bioartificial human dermis substitute by tissue engineering to treat infected wounds using fibrin-agarose biomaterials functionalized with nanostructured lipid carriers (NLCs) loaded with two anti-Pseudomonas antibiotics: sodium colistimethate (SCM) and amikacin (AMK).ResultsResults show that the novel tissue-like substitutes have strong antibacterial effect on Pseudomonas cultures, directly proportional to the NLC concentration. Free DNA quantification, WST-1 and Caspase 7 immunohistochemical assays in the functionalized dermis substitute demonstrated that neither cell viability nor cell proliferation were affected by functionalization in most study groups. Furthermore, immunohistochemistry for PCNA and KI67 and histochemistry for collagen and proteoglycans revealed that cells proliferated and were metabolically active in the functionalized tissue with no differences with controls. When functionalized tissues were biomechanically characterized, we found that NLCs were able to improve some of the major biomechanical properties of these artificial tissues, although this strongly depended on the type and concentration of NLCs.ConclusionsThese results suggest that functionalization of fibrin-agarose human dermal substitutes with antibiotic-loaded NLCs is able to improve the antibacterial and biomechanical properties of these substitutes with no detectable side effects. This opens the door to future clinical use of functionalized tissues.

Highlights

Treatment of patients affected by severe burns is challenging, especially due to the high risk of Pseudomonas infection
Biocompatibility analysis Quantification of DNA released to the culture medium as a result of cell damage revealed that most experimental conditions were associated to very low levels of DNA (Table 1)
After 24 h, we found that the lowest concentrations of each type of Nanostructured lipid carriers (NLC) (10 and 100 μg/ml) were not associated to significant levels of released DNA

Summary

Introduction

Treatment of patients affected by severe burns is challenging, especially due to the high risk of Pseudomonas infection. We have generated a novel model of bioartificial human dermis substitute by tissue engineering to treat infected wounds using fibrin-agarose biomaterials functionalized with nanostructured lipid carriers (NLCs) loaded with two anti-Pseudomonas antibiotics: sodium colistimethate (SCM) and amikacin (AMK). Among the different biomaterials that showed preclinical and clinical usefulness for the generation of human tissue substitutes, fibrin-agarose hydrogels show excellent biocompatibility and biomechanical properties and its porous fibrillar pattern allows diffusion and interchange of oxygen and nutrients [2, 3, 5, 6]. A bioartificial model of tissue-engineered human skin (UGRSKIN), consisting of a dermal skin substitute based on fibrin-agarose biomaterials and dermal fibroblasts and an overlying epithelial layer, has been successfully translated to the clinical setting [16]. Preliminary clinical results of this model are very positive, further research is needed in order to enhance the biological properties of these bioartificial tissues and improve their clinical efficiency

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Discussion

Conclusion