In vivo degradation behavior of enzyme-degradable poly(trimethylene carbonate)-based biohybrid networks of varying water content

2020 ◽  
Vol 15 (2) ◽  
pp. 025001
Author(s):  
Shadi Taghavi ◽  
Brian G Amsden
Polymer ◽  
2014 ◽  
Vol 55 (20) ◽  
pp. 5111-5124 ◽  
Author(s):  
Liqun Yang ◽  
Jianxin Li ◽  
Shu Meng ◽  
Ying Jin ◽  
Jinzhe Zhang ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 946
Author(s):  
Katharina Kowalewicz ◽  
Elke Vorndran ◽  
Franziska Feichtner ◽  
Anja-Christina Waselau ◽  
Manuel Brueckner ◽  
...  

Calcium magnesium phosphate cements (CMPCs) are promising bone substitutes and experience great interest in research. Therefore, in-vivo degradation behavior, osseointegration and biocompatibility of three-dimensional (3D) powder-printed CMPC scaffolds were investigated in the present study. The materials Mg225 (Ca0.75Mg2.25(PO4)2) and Mg225d (Mg225 treated with diammonium hydrogen phosphate (DAHP)) were implanted as cylindrical scaffolds (h = 5 mm, Ø = 3.8 mm) in both lateral femoral condyles in rabbits and compared with tricalcium phosphate (TCP). Treatment with DAHP results in the precipitation of struvite, thus reducing pore size and overall porosity and increasing pressure stability. Over 6 weeks, the scaffolds were evaluated clinically, radiologically, with Micro-Computed Tomography (µCT) and histological examinations. All scaffolds showed excellent biocompatibility. X-ray and in-vivo µCT examinations showed a volume decrease and increasing osseointegration over time. Structure loss and volume decrease were most evident in Mg225. Histologically, all scaffolds degraded centripetally and were completely traversed by new bone, in which the remaining scaffold material was embedded. While after 6 weeks, Mg225d and TCP were still visible as a network, only individual particles of Mg225 were present. Based on these results, Mg225 and Mg225d appear to be promising bone substitutes for various loading situations that should be investigated further.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1438
Author(s):  
Silvio Curia ◽  
Feifei Ng ◽  
Marie-Emérentienne Cagnon ◽  
Victor Nicoulin ◽  
Adolfo Lopez-Noriega

This article presents the evaluation of diblock and triblock poly(ethylene glycol)-b-poly(1,3-trimethylene carbonate) amphiphilic copolymers (PEG-PTMCs) as excipients for the formulation of long-acting injectables (LAIs). Copolymers were successfully synthesised through bulk ring-opening polymerisation. The concomitant formation of PTMC homopolymer could not be avoided irrespective of the catalyst amount, but the by-product could easily be removed by gel chromatography. Pure PEG-PTMCs undergo faster erosion in vivo than their corresponding homopolymer. Furthermore, these copolymers show outstanding stability compared to their polyester analogues when formulated with amine-containing reactive drugs, which makes them particularly suitable as LAIs for the sustained release of drugs susceptible to acylation.


2011 ◽  
Vol 88 (1) ◽  
pp. 254-259 ◽  
Author(s):  
Huanxin Wang ◽  
Shaokang Guan ◽  
Yisheng Wang ◽  
Hongjian Liu ◽  
Haitao Wang ◽  
...  

Biomaterials ◽  
2006 ◽  
Vol 27 (9) ◽  
pp. 1741-1748 ◽  
Author(s):  
Zheng Zhang ◽  
Roel Kuijer ◽  
Sjoerd K. Bulstra ◽  
Dirk W. Grijpma ◽  
Jan Feijen

2006 ◽  
Vol 7 (1) ◽  
pp. 365-372 ◽  
Author(s):  
Brian G. Amsden ◽  
M. Yat Tse ◽  
Norma D. Turner ◽  
Darryl K. Knight ◽  
Stephen C. Pang

2018 ◽  
Vol 41 (11) ◽  
pp. 772-778 ◽  
Author(s):  
Sara R Knigge ◽  
Birgit Glasmacher

A lot of research has been done in the field of magnesium-based implant material. This study is focused on finding an explanation for the large disparity in results from similar experiments in literature. The hypothesis is that many different measurement protocols are used to quantify magnesium degradation and this leads to inconsistent results. Cylindrical, pure magnesium samples were used for this study. The degradation took place in revised simulated body fluid at 37°C. Hydrogen evolution was measured to quantify the degradation. Two commonly used experimental protocols were examined: static conditions and a fluid changing method. For static testing, the samples stayed in fluid. For the fluid changing method, the fluid was changed after 2 and 5 days of immersion. In addition, a new method with continuous fluid flow was established. After an initial phase, the results confirm that for all three methods, the degradation behavior differs strongly. The static condition results in a very slow degradation rate. The fluid change method leads to a similar behavior like the static condition except that the degradation was speeded up after the fluid changes. The continuous degradation is linear for a long period after the initial phase. In comparison with in vivo degradation behavior, the degradation process in continuous flow shows the best fitting. The accumulation of degradation products, especially the increasing pH value, has a strong inhibiting effect. This cannot be observed in vivo so that a constant experimental environment realizable by continuous flow is more suitable for magnesium-based implant material testing.


2009 ◽  
Vol 1190 ◽  
Author(s):  
Bernhard Hiebl ◽  
Karl Kratz ◽  
Rosemarie Fuhrmann ◽  
Friedrich Jung ◽  
Andres Lendlein ◽  
...  

AbstractThe degradation behavior of biodegradable multiblock copolymers (PDC) containing poly(p-dioxanone) hard segments (PPDO) and crystallizable poly(epsilon-caprolactone) switching segments (PCL) synthesized via co-condensation of two oligomeric macrodiols with an aliphatic diisocyanate as junction unit was explored in in vivo and in vitro experiments. The in vitro experiments for enzymatic degradation resulted that the poly(epsilon-caprolactone) segments are degraded faster, than the poly(p-dioxanone) segments. During degradation the outer layer of the test specimen becomes porous. Finally non-soluble degradation products in form of particles were found at the surface. This observation is in good agreement with the in vivo studies, where the non-soluble degradation products in the periimplantary tissues showed a diameter of 1 – 3 micron.


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