The aim of this work was to assess the use of injectable and biocompatible hydrogel-based tools for the controlled release of active proteins against neurodegenerative disorders like Alzheimer’s (AD) and Parkinson’s (PD) diseases. The hydrogels studied in this work have been divided in 3 categories accordingly to the origin of their components. Natural hydrogels are composed of Collagen (COLL) and Hyaluronic Acid (HA) in its low molecular weight conformation (LMWHA) and high (HMW HA). Regarding semi-synthetic hydrogels COLL was studied at two different concentrations (1.2 and 1.8mg/mL) in combination with poly(ethylene glycol) (PEG). The effects of adding poly(ethylene oxide), tetrasuccinimidyl glutarate terminated (4S-Star PEG) as a crosslinker were evaluated. Synthetic hydrogels are composed of poly(N-isopropylacrylamide) (PNIPAM), chosen for its termosensitivity and studied at 2 different concentrations (200 and 300mg/mL), alone and in combination with PEG. The mechanical moduli of natural and semi-synthetic hydrogels showed to be generally higher than COLL ones in the investigated frequency range, the COLL-LMW HA gel only until 4.5Hz; they showed a gel-like behavior and injectability through a 30G needle, with maximum load values generally ranging from 3.0 to 3.9 N, the COLL-HMW HA gel showed values above 6N. In vitro results showed that SH-SY5Y cells kept their proliferative potential and viability after embedding in natural and COLL-PEG gels. COLL-PEG gels also showed to be able to release proteins in vitro. Synthetic hydrogels showed high values of elastic and loss moduli and viscosity, with a gel-like behavior only at frequencies above 0.23Hz. Synthetic gels and semi-synthetic matrices containing 4S-Star PEG showed viability values of SH-SY5Y cells significantly lower when compared to the natural and COLL-PEG ones. In conclusion, COLL-LMW HA and COLL-PEG hydrogels showed optimal viscoelastic properties, flow behaviour, functional injectability and in vitro biological performance. These findings represent a crucial starting point for the development of minimally invasive and injectable hydrogel-based tools for innovative drug delivery against AD, PD.
Lo scopo di questo lavoro è stato quello di testare l'uso di idrogeli iniettabili e biocompatibili per il rilascio controllato di proteine attive contro malattie neurodegenerative come Alzheimer e Parkinson. Gli idrogeli studiati in questo lavoro sono stati divisi in 3 categorie a seconda dell'origine dei loro componenti. I gel naturali sono composti da Collagene (COLL) e Acido Ialuronico (HA) a basso (LMW HA) e alto peso molecolare (HMW HA). Riguardo agli idrogeli semi-sintetici, il COLL è stato studiato a 2 concentrazioni (1,2 e 1,8mg/ml) in combinazione con il poli(etilen-glicolo) (PEG). Gli effetti dell' aggiunta di tetrasuccimidil-glutarato terminato (4S-Star PEG) come cross-linkante sono stati valutati. Gli idrogeli sintetici sono composti da poli(N-isopropilacrilammide) (PNIPAM), scelto per la sua termosensitività e studiato alle concentrazioni di 200 e 300mg/ml, da solo e in combinazione con PEG. I moduli viscoelastici dei gel naturali e semi-sintetici hanno mostrato generalmente di essere superiori a quelli del COLL nel range di frequenze investigato, il gel COLL- LMW HA fino a circa 4,5Hz; hanno anche mostrato un comportamento gel-like e iniettabilità attraverso un ago 30G, con valori di carico massimo che generalmente variano da 3.0 a 3.9N, il gel COLL-HMW HA oltre i 6N. Risultati dai test in vitro hanno mostrato che le cellule SH-SY5Y mantengono potenziale proliferativo e vitalità dopo essere state coltivate all'interno dei gel naturali e COLL-PEG. I gel COLL-PEG hanno anche mostrato di poter rilasciare proteine in vitro. Gli idrogeli sintetici hanno mostrato alti valori di moduli meccanici e viscosità, con un comportamento gel-like solo a frequenze oltre 0,23Hz. I gel sintetici e le matrici semi-sintetiche contenenti 4S-Star PEG hanno mostrato valori di vitalità delle cellule SH-SY5Y significativamente inferiori rispetto ai gel naturali e COLL-PEG. In conclusione, i gel COLL-LMW HA e COLL-PEG hanno mostrato ottime proprietà viscoelastiche, iniettabilità funzionale e citocompatibilità in vitro. Questi risultati rappresentano un punto di partenza per lo sviluppo di idrogeli iniettabili e minimamente invasivi per il rilascio di proteine contro AD e PD.
Design and development of engineered hydrogel based tools for neurodegeneration
BARBIERI, LUCA
2013/2014
Abstract
The aim of this work was to assess the use of injectable and biocompatible hydrogel-based tools for the controlled release of active proteins against neurodegenerative disorders like Alzheimer’s (AD) and Parkinson’s (PD) diseases. The hydrogels studied in this work have been divided in 3 categories accordingly to the origin of their components. Natural hydrogels are composed of Collagen (COLL) and Hyaluronic Acid (HA) in its low molecular weight conformation (LMWHA) and high (HMW HA). Regarding semi-synthetic hydrogels COLL was studied at two different concentrations (1.2 and 1.8mg/mL) in combination with poly(ethylene glycol) (PEG). The effects of adding poly(ethylene oxide), tetrasuccinimidyl glutarate terminated (4S-Star PEG) as a crosslinker were evaluated. Synthetic hydrogels are composed of poly(N-isopropylacrylamide) (PNIPAM), chosen for its termosensitivity and studied at 2 different concentrations (200 and 300mg/mL), alone and in combination with PEG. The mechanical moduli of natural and semi-synthetic hydrogels showed to be generally higher than COLL ones in the investigated frequency range, the COLL-LMW HA gel only until 4.5Hz; they showed a gel-like behavior and injectability through a 30G needle, with maximum load values generally ranging from 3.0 to 3.9 N, the COLL-HMW HA gel showed values above 6N. In vitro results showed that SH-SY5Y cells kept their proliferative potential and viability after embedding in natural and COLL-PEG gels. COLL-PEG gels also showed to be able to release proteins in vitro. Synthetic hydrogels showed high values of elastic and loss moduli and viscosity, with a gel-like behavior only at frequencies above 0.23Hz. Synthetic gels and semi-synthetic matrices containing 4S-Star PEG showed viability values of SH-SY5Y cells significantly lower when compared to the natural and COLL-PEG ones. In conclusion, COLL-LMW HA and COLL-PEG hydrogels showed optimal viscoelastic properties, flow behaviour, functional injectability and in vitro biological performance. These findings represent a crucial starting point for the development of minimally invasive and injectable hydrogel-based tools for innovative drug delivery against AD, PD.| File | Dimensione | Formato | |
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https://hdl.handle.net/10589/102061