RESUMO
Hydrogels are perfectly suited to support cell and tissue growth in advanced tissue engineering applications as well as classical wound treatment scenarios. Ideal hydrogel materials for these applications should be easy to produce, biocompatible, resorbable and antimicrobial. Here we report the fabrication of degradable covalent antimicrobial lysine and tryptophan containing copolypeptide hydrogels, whereby the hydrogel properties can be independently modulated by the copolypeptide monomer ratio and chiral composition. Well-defined statistical copolypeptides comprising different overall molecular weights as well as ratios of l- and d-lysine and tryptophan at ratios of 35 : 15, 70 : 30 and 80 : 20 were obtained by N-carboxyanhydride (NCA) polymerisation and subsequently crosslinked by the selective reaction of bifunctional triazolinedione (TAD) with tryptophan. Real-time rheology was used to monitor the crosslinking reaction recording the fastest increase and overall modulus for copolypeptides with the higher tryptophan ratio. Water uptake of cylindrical hydrogel samples was dependent on crosslinking ratio but found independent of chiral composition, while enzymatic degradation proceeded significantly faster for samples containing more l-amino acids. Antimicrobial activity on a range of hydrogels containing different polypeptide chain lengths, lysine/tryptophan composition and l/d enantiomers was tested against reference laboratory strains of Gram-negative Escherichia coli (E. coli; ATCC25922) and Gram-positive, Staphylococcus aureus (S. aureus; ATCC25923). log reductions of 2.8-3.4 were recorded for the most potent hydrogels. In vitro leachable cytotoxicity tests confirmed non-cytotoxicity as per ISO guidelines.
Assuntos
Antibacterianos/farmacologia , Materiais Biocompatíveis/farmacologia , Reagentes de Ligações Cruzadas/farmacologia , Hidrogéis/farmacologia , Peptídeos/farmacologia , Triazóis/farmacologia , Antibacterianos/química , Antibacterianos/metabolismo , Materiais Biocompatíveis/química , Materiais Biocompatíveis/metabolismo , Reagentes de Ligações Cruzadas/química , Reagentes de Ligações Cruzadas/metabolismo , Escherichia coli/efeitos dos fármacos , Humanos , Hidrogéis/química , Hidrogéis/metabolismo , Testes de Sensibilidade Microbiana , Peptídeos/química , Peptídeos/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Triazóis/química , Triazóis/metabolismoRESUMO
We show that filamentous fungi can emit green or red light after the accumulation of particulate lanthanide metal-organic frameworks over the cell wall. These new biohybrids present photoluminescence properties that are unaffected by the components of the cell wall. In addition, the fungal cells internalise lanthanide metal-organic framework particles, storing them into organelles, thereby making these materials promising for applications in living imaging studies.
Assuntos
Fungos/metabolismo , Microscopia Intravital/métodos , Elementos da Série dos Lantanídeos/química , Luminescência , Estruturas Metalorgânicas/química , Cor , Citoplasma/química , Citoplasma/metabolismo , Citoplasma/efeitos da radiação , Estudos de Viabilidade , Fungos/química , Fungos/citologia , Fungos/efeitos da radiação , Elementos da Série dos Lantanídeos/metabolismo , Elementos da Série dos Lantanídeos/efeitos da radiação , Medições Luminescentes/métodos , Estruturas Metalorgânicas/metabolismo , Estruturas Metalorgânicas/efeitos da radiação , Técnicas Microbiológicas/métodos , Organelas/química , Organelas/metabolismo , Organelas/efeitos da radiação , Raios UltravioletaRESUMO
This communication describes a general method for templating fungal filaments with gold nanoparticles that results in a gold replica of filaments after calcination of the biological template.
