Multifunctional Biodegradable Vascular PLLA Scaffold with Improved X-ray Opacity, Anti-Inflammation, and Re-Endothelization

Abstract

Poly(L-lactic acid) (PLLA) has been used as a biodegradable vascular scaffold (BVS) material due to high mechanical property, biodegradability, and biocompatibility. However, acidic byproducts from hydrolysis of PLLA reduce the pH after the surrounding implanted area and cause inflammatory responses. As a result, severe inflammation, thrombosis, and in-stent restenosis can occur after implantation by using BVS. Additionally, polymers such as PLLA could not find on X-ray computed tomography (CT) because of low radiopacity. To this end, here, we fabricated PLLA films as the surface of BVS and divided PLLA films into two coating layers. At the first layer, PLLA film was coated by 2,3,5-triiodobenzoic acid (TIBA) and magnesium hydroxide (MH) with poly(D,L-lactic acid) (PDLLA) for radiopaque and neutralization of acidic environment, respectively. The second layer of coated PLLA films is composed of polydopamine (PDA) and then cystamine (Cys) for the generation of nitric oxide (NO) release, which is needed for suppression of smooth muscle cells (SMCs) and proliferation of endothelial cells (ECs). The characterization of the film surface was conducted via various analyses. Through the surface modification of PLLA films, they have multifunctional abilities to overcome problems of BVS effectively such as X-ray penetrability, inflammation, thrombosis, and neointimal hyperplasia. These results suggest that the modification of biodegradable PLLA using TIBA, MH, PDA, and Cys will have important potential in implant applications.

Poly(L-Lactic Acid) Composite with Surface-Modified Magnesium Hydroxide Nanoparticles by Biodegradable Oligomer for Augmented Mechanical and Biological Properties

“…However, the pH of the PLLA/MH, PLLA/MH-ODLLA, PLLA/MH-OLCL7, and PLLA/MH-OLCL15 dropped slowly for 7 days to reach pH 7.03, 6.66, 6.46, and 6.63, respectively, due to the neutralization ability of MH and surface-modified MH nanoparticles. To overcome the pH decrease of the degradation processing, significant research was performed using inorganic compounds such as calcium carbonate and sodium bicarbonate and they were incorporated into the PLLA to determine their effect on the degradation [ 35 , 36 ]. Especially, MH nanoparticles can neutralize the acidic condition because the dehydrated magnesium ions can bind with part of the anionic compounds [ 36 ].…”

Development of Biodegradable Polymeric Stents for the Treatment of Cardiovascular Diseases

“…As an attempt to prepare the visible coating, Lee et al [ 67 ] applied the coating on the surface of the PLLA material. The coating was composed of 2, 3, 5-triiodobenzoic acid (TIBA), magnesium hydroxide (MH), and poly ( d -L-lactic acid) (PDLLA).…”

Comparison of Surface Functionalization of PLGA Composite to Immobilize Extracellular Vesicles

“…The chemical bonding of the surface was determined by ATR-FTIR in the range of 650-4000 cm −1 and scan speed (0.2 cm/s). For XPS condition, microfocus X-ray (1486.6 eV) was used with charging correction (adventitious carbon, 284.8 eV) and dual neutralizer (Ar ion + electrons) [31,32]. The pH changes were measured by a pH meter (Mettler Toledo, Columbus, OH, USA) in 5 mL of PBS solution containing Proteinase K at 37 • C for 14 days.…”

“…PLGA is widely recognized as a biocompatible and biodegradable biomaterial and has already been widely used in clinics [29]. We previously established that PLGA-based biodegradable implants containing magnesium hydroxide (MH) effectively alleviated the adverse effects induced by acidic PLGA byproducts [30,31]. In addition, decellularized extracellular matrix (dECM) is extensively used as a platform for the bioengineering of medical implants to enhance and control the interaction between implants and host tissues [32].…”