Medical-Grade Poly(Lactic Acid)/Hydroxyapatite Composite Films: Thermal and In Vitro Degradation Properties

Abstract

Production of biocompatible composite scaffolds shifts towards additive manufacturing where thermoplastic biodegradable polymers such as poly(lactic acid) (PLA) are used as matrices. Differences between industrial- and medical-grade polymers are often overlooked although they may affect properties and degradation behaviour as significantly as the filler addition. In the present research, composite films based on medical-grade PLA and biogenic hydroxyapatite (HAp) with 0, 10, and 20 wt.% of HAp were prepared by solvent casting technique. The degradation of composites incubated in phosphate-buffered saline solution (PBS) at 37 °C after 10 weeks showed that the higher HAp content slowed down the hydrolytic PLA degradation and improved its thermal stability. Morphological nonuniformity after degradation was indicated by the different glass transition temperatures (Tg) throughout the film. The Tg of the inner part of the sample decreased significantly faster compared with the outer part. The decrease was observed prior to the weight loss of composite samples.

Development of bioactive short fiber-reinforced printable hydrogels with tunable mechanical and osteogenic properties for bone repair

“…As one of the commonly used biodegradable polymers for bone tissue engineering, PLA is classified as a slow-degrading polymer both in vitro and in vivo . 52,53 In vitro degradation under physiological conditions and at higher temperatures (70 °C) is reported elsewhere 54,55 suggesting the long-term degradation behavior of PLA as well as the effect of HA coating on PLA degradation. 52,56 Hence, we presume from existing literature that PLA degradation occurs in the long term while they can aid in mechanical strength during bulk scaffold degradation.”…”

The Structural, Thermal and Morphological Characterization of Polylactic Acid/Β-Tricalcium Phosphate (PLA/Β-TCP) Composites upon Immersion in SBF: A Comprehensive Analysis

“…After 7 days, PLA/10β-TCP and PLA/20β-TCP biocomposites exhibited almost constant mass loss, corresponding to a stable calcium concentration as well ( Figure 5 a). In contrast, PLA/25βTCP continued to release calcium into the SBF solution due to the dissolution of β-TCP in SBF [ 9 , 30 ]. Figure 5 d shows a slight increase in pH values during the immersion time for β-TCP and PLA/β-TCP composites.…”

“…PLA presently occupies the most important position in medical resorbable implants given its favorable characteristics, such as compatibility with human tissue, nontoxicity, durability, biodegradability, and rigidity [ 4 , 5 , 6 ]. The literature presents numerous approaches [ 4 , 7 , 8 , 9 , 10 , 11 , 12 ] to improve PLA bioactivity, resorbability, and hydrophilicity with the combination of bioactive fillers and surface engineering. One of the most employed is β-tricalcium phosphate (β-TCP), which has attracted much attention in medical research due to its excellent biocompatibility, osteoconduction ability, and reabsorption when implanted.…”

A Photothermal Therapy Study Based on Electrospinning Nanofibers Blended and Coated with Polydopamine Nanoparticles

“…Among many such materials, poly‐L‐lactic acid (PLLA) has many advantages, including non‐toxic, non‐irritating, biodegradable and absorbable, high strength, good plasticity [14–16] . Even more importantly, PLLA could be decomposed by enzymes in the living body and finally form carbon dioxide and water, making it a potential application in drug delivery and tissue regeneration [17,18] …”

“…[14][15][16] Even more importantly, PLLA could be decomposed by enzymes in the living body and finally form carbon dioxide and water, making it a potential application in drug delivery and tissue regeneration. [17,18] Inspired by natural melanin, the nontoxic mussel biopolymer, and good adhesion of mussel, polydopamine nanoparticles (PDA NPs) have attracted increasing attention on drug delivery, bioimaging, blood-compatibility and biodegradability, [19] and most strikingly, surface modifications and the photothemal efficacy. [20,21] In fact, the report for PDA NPs functionalized PLLA polymer has been discussed by modifying PLLA, thus enhancing the mechanical properties.…”