A Facile Composite Strategy to Prepare a Biodegradable Polymer Based Radiopaque Raw Material for “Visualizable” Biomedical Implants

Abstract

Enabling a biodegradable polymer radiopaque under X-ray is much desired for many medical devices. Physical blending of a present biodegradable polymer and a commercialized medical contrast agent is convenient yet lacks comprehensive fundamental research. Herein, we prepared a biodegradable polymer-based radiopaque raw material by blending poly(L-lactic acid) (PLLA or simply PLA) and iohexol (IHX), where PLA constituted the continuous phase and IHX particles served as the dispersed phase. The strong X-ray adsorption of IHX enabled the composite radiopaque; the hydrolysis of the polyester and the water solubility of the contrast agent enabled the composite biodegradable in an aqueous medium. The idea was confirmed by in vitro characterizations of the resultant composite, in vivo subcutaneous implantation in rats up to 6 months, and the clear visualization of a part of a biodegradable occluder in a Bama piglet under X-ray. We also found that the crystallization of PLA was significantly enhanced in the presence of the solid particles, which should be taken into consideration in the design of an appropriate biomaterial composite because crystallization degree influences the biodegradation rate and mechanical property of a material to a large extent. We further tried to introduce a small amount of poly(vinylpyrrolidone) into the blend of PLA and IHX. Compared to the bicomponent composite, the tricomponent one exhibited decreased modulus and increased elongation at break and tensile strength. This paves more ways for researchers to select appropriate raw materials according to the regenerated tissue and the application site.

Stereo Coverage and Overall Stiffness of Biomaterial Arrays Underly Parts of Topography Effects on Cell Adhesion

“…We employed the mold casting method to fabricate the patterned surfaces, as schematically presented in Figure S2, and the topography was controlled with varied array parameters, in particular, heights and diameters. Here, we choose PLLA as the raw material because PLLA as well as its copolymer such as poly­(lactide- co -glycolide) (PLGA) is a kind of polymeric biomaterials widely used in biodegradable implants, − and we choose human umbilical vein endothelial cells (HUVECs) as the model cell type because this is an important cell type widely used in biomaterial studies, in particular for cardiovascular systems. − Roughness, plateau coverage, stereo coverage, and overall stiffness were calculated and correlated to adhesion behaviors of cells on different micropatterns. It is verified that these important parameters can semi-quantify the effects of surface topography on cell adhesion.…”

Achieving Long-Acting Local Analgesia Using an Intelligent Hydrogel Encapsulated with Drug and pH Regulator

“…Their drug existed in the form of ropivacaine base nanoparticles prior to being encapsulated in the biomacromolecular hydrogel. Among various biomaterials, − the PLGA–PEG-PLGA hydrogel distinguishes itself as an intelligent synthetic biomaterial that can respond to the change of temperature and exhibits a sol–gel transition with spontaneous physical gelation upon heating. Ding and Chen et al even loaded an anesthetic drug into a pertinent polymeric aqueous solution with BUP, which was injected near the nerve to achieve local analgesia .…”

A Biodegradable Metal‐Polymer Composite Stent Safe and Effective on Physiological and Serum‐Containing Biomimetic Conditions

“…The next-generation biomaterials are regarded as bioactive and biodegradable. [41] Both cell-material interactions [42][43][44][45][46][47][48][49][50][51][52] and biodegradation regulations [53][54][55][56][57][58] have been investigated, and even some in vivo studies in animal models and clinical research have been reported. [59][60][61][62] It also leads to a serious question about the biosafety along the biodegradation.…”