In vitro and in vivo degradation profile of aliphatic polyesters subjected to electron beam sterilization

Dånmark, Staffan; Finne‐Wistrand, Anna; Schander, Kerstin; Hakkarainen, Minna; Arvidson, Kristina; Mustafa, Kamal; Albertsson, Ann‐Christine

doi:10.1016/j.actbio.2011.02.011

Cited by 66 publications

(66 citation statements)

References 37 publications

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“…[ 30 ] Previously, it was demonstrated that the PLCL scaffolds implanted in rat calvaria decrease their molecular weight by around 70% after 91 days. [ 26 ] Regarding these same unmodifi ed scaffolds, our study showed in two months almost 60% of M n is reduced. Hence comparable rate of degradation is seen although the implantation site and size of animal was different.…”

Section: Discussionmentioning

confidence: 61%

“…[ 26 ] In the current study, the explanted scaffolds were extracted with chloroform, and the polymeric residue was weighed and analyzed, thus demonstrating that the degradation of the scaffolds occurred by polymer chain cleavage, resulting in a reduction of molecular weight. These polyesters are known to degrade by hydrolysis.…”

Section: Discussionmentioning

confidence: 80%

“…The degradation analyzed after week 1 is relatively fast, but may be the result of pre-existing water soluble low molecular weight oligomers created during sterilization being leached out without need for chain cleavage. [ 26 ] It was also observed that the increased water diffusion into the nDP modifi ed scaffolds may have promoted a bulk pattern of erosion. In bulk erosion, the polymer chain scission occurs throughout the scaffold in the amorphous part of the polymer, thus although it does not change much in external dimensions, the molecular weight decreases early.…”

Section: Full Papermentioning

confidence: 99%

“…[ 25 ] The degradation profi le of pristine poly[( L -lactide)-co-(ε-caprolactone)] (PLCL) scaffolds has been previously reported, however only for up to 13 weeks in vivo. [ 26 ] The effect of nDP modifi cation and BMP-2 physisorption on the degradation of these scaffolds has not been studied yet. Thus, the main objective of this work was to determine in vivo the effect of functionalizing PLCL scaffolds with nDP and nDP plus BMP-2 on degradation and on the infl ammatory and healing response up to 27 weeks.…”

Section: Introductionmentioning

confidence: 99%

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In Vivo Host Response and Degradation of Copolymer Scaffolds Functionalized with Nanodiamonds and Bone Morphogenetic Protein 2

Suliman

Sun

Pedersen

et al. 2016

Adv Healthcare Materials

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The aim is to evaluate the effect of modifying poly[( L -lactide)-co-(ε-caprolactone)] scaffolds (PLCL) with nanodiamonds (nDP) or with nDP+physisorbed BMP-2 (nDP+BMP-2) on in vivo host tissue response and degradation. The scaffolds are implanted subcutaneously in Balb/c mice and retrieved after 1, 8, and 27 weeks. Molecular weight analysis shows that modifi ed scaffolds degrade faster than the unmodifi ed. Gene analysis at week 1 shows highest expression of proinfl ammatory markers around nDP scaffolds; although the presence of infl ammatory cells and foreign body giant cells is more prominent around the PLCL. Tissue regeneration markers are highly expressed in the nDP+BMP-2 scaffolds at week 8. A fi brous capsule is detectable by week 8, thinnest around nDP scaffolds and at week 27 thickest around PLCL scaffolds. mRNA levels of ALP, COL1α2, and ANGPT1 are signifi cantly upregulating in the nDP+BMP-2 scaffolds at week 1 with ectopic bone seen at week 8. Even when almost 90% of the scaffold is degraded at week 27, nDP are observable at implantation areas without adverse effects. In conclusion, modifying PLCL scaffolds with nDP does not aggravate the host response and physisorbed BMP-2 delivery attenuates infl ammation while lowering the dose of BMP-2 to a relatively safe and economical level.

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Section: Discussionmentioning

confidence: 61%

Section: Discussionmentioning

confidence: 80%

Section: Full Papermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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In Vivo Host Response and Degradation of Copolymer Scaffolds Functionalized with Nanodiamonds and Bone Morphogenetic Protein 2

Suliman

Sun

Pedersen

et al. 2016

Adv Healthcare Materials

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“…For example, they are employed in the pulsed plasma chemical technology, which is applied to synthesize the nanosized metal oxides, [1][2][3][4][5][6] and in the pulsed technology, which allows industrial and domestic wastewater treatment and disinfection, 7,8 etc. 9,10 Nowadays, there are many experimental and theoretical works studying the electron beam propagation in different gases [11][12][13][14][15][16][17][18][19][20] and the main characteristics of an electron beam behaviour during its propagation.…”

Section: Introductionmentioning

confidence: 99%

Pulsed electron beam propagation in argon and nitrogen gas mixture

et al. 2015

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Pulsed electron beam propagation in argon and nitrogen gas mixture, 2015, Physics of Plasmas, (22) The paper presents the results of current measurements for the electron beam, propagating inside a drift tube filled in with a gas mixture (Ar and N 2 ). The experiments were performed using the TEA-500 pulsed electron accelerator. The main characteristics of electron beam were as follows: 60 ns pulse duration, up to 200 J energy, and 5 cm diameter. The electron beam propagated inside the drift tube assembled of three sections. Gas pressures inside the drift tube were 760 6 3, 300 6 3, and 50 6 1 Torr. The studies were performed in argon, nitrogen, and their mixtures of 33%, 50%, and 66% volume concentrations, respectively. V C 2015 AIP Publishing LLC.

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In situ dynamic vulcanization process in preparation of electrically conductive PP/EPDM thermoplastic vulcanizate/expanded graphite nanocomposites: Effects of state of cure

Ranjbar

Mirzazadeh

Katbab

et al. 2011

J of Applied Polymer Sci

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In situ melt dynamic vulcanization process has been employed to prepare electrically conductive polypropylene (PP)/ethylene-propylene-diene rubber (EPDM) (40/60 wt %) thermoplastic vulcanizates (TPVs) incorporated by expanded graphite (EG) as a conductive filler. Maleic anhydride grafted PP (PP-g-MAH) was used as compatibilizer and a sulfur curing system was designed and incorporated to vulcanize the EPDM phase during mixing process. Developed microstructures were characterized using scanning electron microscopy (SEM), melt rheomechanical spectroscopy (RMS), X-ray diffraction (XRD), and transmission electron microscopy (TEM) and were correlated with electrical conductivity behavior. For comparison, another class of TPV/EG nanocomposites was fabricated using a commercially available PP/EPDMbased TPV via both direct and masterbatch melt mixing process. Conductivity of the nanocomposites prepared by in situ showed no significant change during dynamic vulcanization till the mixing torque reached to the stationary level where micro-morphology of the cured rubber droplets was fully developed, and conductivity abrupt was observed. In situ cured nanocomposites showed higher insulator to conductor transition threshold (3.15 vol % EG) than those based on commercially available TPV. All electrically conductive in situ prepared TPV nanocomposites exhibited reinforced melt elasticity with pseudosolid-like behavior within low frequency region in dynamic melt rheometry indicating formation of physical networks by both EG nanolayers and crosslinked EPDM droplets.

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In vitro and in vivo degradation profile of aliphatic polyesters subjected to electron beam sterilization

Cited by 66 publications

References 37 publications

In Vivo Host Response and Degradation of Copolymer Scaffolds Functionalized with Nanodiamonds and Bone Morphogenetic Protein 2

In Vivo Host Response and Degradation of Copolymer Scaffolds Functionalized with Nanodiamonds and Bone Morphogenetic Protein 2

Pulsed electron beam propagation in argon and nitrogen gas mixture

In situ dynamic vulcanization process in preparation of electrically conductive PP/EPDM thermoplastic vulcanizate/expanded graphite nanocomposites: Effects of state of cure

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