Influence of polymer processing technique on long term degradation of poly(ε-caprolactone) constructs

Natu, Mădălina V.; Sousa, Hermínio C. de; Gil, M.H.

doi:10.1016/j.polymdegradstab.2012.10.030

Cited by 24 publications

(21 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is in good agreement with results obtained by Lam et al [8]. In the case of composites, no further changes or even decrease in T m after 15 months was observed, suggesting that hydrolysis extended to crystalline regions of PCL [28]. As shown in Fig.…”

Section: In Vitro Degradationsupporting

confidence: 92%

“…Therefore, an increase in the crystallinity fraction of polymer over degradation time was expected. Moreover, increase in T m during incubation can also indicate recrystallization process of PCL and a formation of larger polymer crystallite structure [27,28]. The hydrolysis of polymer chains increases possibility of recrystallization by reducing their length and increasing mobility.…”

Section: In Vitro Degradationmentioning

confidence: 99%

“…The hydrolysis of polymer chains increases possibility of recrystallization by reducing their length and increasing mobility. Furthermore, because of low glass transition temperature of PCL (-60°C) mobility of non-degraded chains at 37°C during incubation in aqueous media could be enhanced and solvent-induced crystallization might have occurred [8,[28][29][30]. Although the crystallinity of PCL film increased, the mass loss was not observed, indicating bulk degradation kinetics.…”

Section: In Vitro Degradationmentioning

confidence: 99%

See 2 more Smart Citations

A new insight into in vitro behaviour of poly(ε-caprolactone)/bioactive glass composites in biologically related fluids

et al. 2017

View full text Add to dashboard Cite

In the present work, the role of content, size and chemical composition of gel-derived bioactive glass particles from the SiO 2 -CaO-P 2 O 5 system in modulating the in vitro bioactivity, osteoinductive properties and long-term (up to 15 months) degradation behaviour of poly(e-caprolactone)-based composite films was investigated. Bioactivity was assessed in simulated body fluid (SBF) and HEPES-free Dulbecco's modified Eagle medium (DMEM) supplemented with 10% foetal bovine serum (FBS), while hydrolytic degradation tests were performed in phosphate buffer saline. Obtained composite films showed excellent calcium phosphate (CaP) layer forming ability in both SBF and DMEM-10% FBS. However, kinetics of bioactivity process strongly depended on the type of medium used. The layer of amino acids and proteins, derived from cell culture medium, on the surfaces of composites created barrier that inhibited release of the ions on the one hand, while increasing nucleation density of calcium phosphates, affecting the morphology of formed CaP layers on the other. The presence of bioactive glass fillers was shown to impart osteoinductive properties to obtained films, supporting osteoblast attachment and proliferation, as well as stimulating cell differentiation and also matrix mineralization process in vitro. We showed that kinetics of bioactivity process and also osteoinductive properties of composite films could be easily modulated with the use of different contents and chemical compositions of fillers. The results showed that modification of PCL matrix with bioactive glass particles accelerated its degradation. We proved that the degradation rate of composites could be controlled and optimized for bone regeneration, in particular by using bioactive fillers causing different calcium phosphate layer forming ability on the surfaces of composites, depending on particle size and chemical composition. We have presented new opportunities to design and obtain multifunctional composites with tunable degradation and bioactivity kinetics, as well as biological properties that can meet complex requirements of bone tissue engineering.

show abstract

Section: In Vitro Degradationsupporting

confidence: 92%

Section: In Vitro Degradationmentioning

confidence: 99%

Section: In Vitro Degradationmentioning

confidence: 99%

See 1 more Smart Citation

A new insight into in vitro behaviour of poly(ε-caprolactone)/bioactive glass composites in biologically related fluids

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Nevertheless, a low intensity peak at 1536 cm -1 (-C=N, stretching) was detected in the F1 spectrum, which was shifted compared with the peak in the DPA spectrum, whereas no peak was observed in the spectrum of F0 fibers. Furthermore, the differences between the spectra of bulk PCL and F1 fibers could be the result of different degree of PCL crystallinity before and after it was dissolved in TFE and electrospun [31]. In addition, formation of hydrogen bonds between the ester groups of PCL (in a semi-crystalline state) and the hydroxyl groups of TFE (in an amorphous state) molecules could explain the shifts in the absorption bands [32,33].…”

Section: Discussionmentioning

confidence: 99%

Pcl/Peg Electrospun Fibers as Drug Carriers for the Controlled Delivery of Dipyridamole

Repanas¹,

Wf²,

O³

et al. 2015

J In Silico In Vitro Pharmacol

View full text Add to dashboard Cite

Electrospinning is a versatile and diverse technology for the production of nano-and microfibers that can be used as a drug delivery system (DDS). The aim of this study was to create fibrous scaffolds from a mixture of polycaprolactone (PCL) and polyethylene glycol (PEG) and to evaluate the suitability of the fibers as DDS. Dipyridamole (DPA), an anti-thrombotic and anti-proliferative pharmaceutical agent, was used as a model drug. Two types of PEG with different chain length were used. The structural, mechanical and physicochemical characteristics of the fibers with and without DPA, were determined, and the release kinetics of DPA were studied. The obtained fibers loaded with DPA and with the higher molecular weight PEG were smooth and had an average diameter of 586.75 ± 204.79 nm and an average Young's modulus of 57.14 ± 4.35 MPa, whereas the tensile strain at break was 0.61 ±0.05 mm/mm and the ultimate tensile strength (UTS) was 16.79 ± 3.08 MPa. The cumulative release of DPA revealed two stages: an initial burst phenomenon followed by slower Fickian diffusion (release exponent n = 0.432).

show abstract

“…19 Based on previous in vivo studies it is estimated that PCL will remain intact for approximately 3 years before losing mechanical integrity. 20,22,23 We investigated a drug delivery device for rapamycin that demonstrates zero-order release behavior up to 14 weeks in vitro. The device is composed of a solid rapamycin pellet encapsulated by two PCL thin films, which can be modified to alter the release profile of the device.…”

mentioning

confidence: 99%

In Vitro and In Vivo Sustained Zero-Order Delivery of Rapamycin (Sirolimus) From a Biodegradable Intraocular Device

Lance

Good

Mendes

et al. 2015

Invest. Ophthalmol. Vis. Sci.

View full text Add to dashboard Cite

PURPOSE. We created implantable intraocular devices capable of constant and continuous rapamycin release on the scale of months to years.METHODS. Polycaprolactone (PCL) thin films were used to encapsulate rapamycin to create implantable and biodegradable intraocular devices. Different film devices were studied by modifying the size, thickness, and porosity of the PCL films.RESULTS. In vitro release of rapamycin was observed to be constant (zero-order) through 14 weeks of study. Release rates were tunable by altering PCL film porosity and thickness. In vivo release of rapamycin was observed out through 16 weeks with concentrations in the retinachoroid in the therapeutic range. Rapamycin concentration in the blood was below the lower limit of quantification. The drug remaining in the device was chemically stable in vitro and in vivo, and was sufficient to last for upwards of 2 years of total release. The mechanism of release is related to the dissolution kinetics of crystalline rapamycin.CONCLUSIONS. Microporous PCL thin film devices demonstrate good ocular compatibility and the ability to release rapamycin locally to the eye over the course of many weeks.

show abstract

Influence of polymer processing technique on long term degradation of poly(ε-caprolactone) constructs

Cited by 24 publications

References 22 publications

A new insight into in vitro behaviour of poly(ε-caprolactone)/bioactive glass composites in biologically related fluids

A new insight into in vitro behaviour of poly(ε-caprolactone)/bioactive glass composites in biologically related fluids

Pcl/Peg Electrospun Fibers as Drug Carriers for the Controlled Delivery of Dipyridamole

In Vitro and In Vivo Sustained Zero-Order Delivery of Rapamycin (Sirolimus) From a Biodegradable Intraocular Device

Contact Info

Product

Resources

About