Recent Advances in Nanocomposites Based on Aliphatic Polyesters: Design, Synthesis, and Applications in Regenerative Medicine

Abstract

In the last decade, biopolymer matrices reinforced with nanofillers have attracted great research efforts thanks to the synergistic characteristics derived from the combination of these two components. In this framework, this review focuses on the fundamental principles and recent progress in the field of aliphatic polyester-based nanocomposites for regenerative medicine applications. Traditional and emerging polymer nanocomposites are described in terms of polymer matrix properties and synthesis methods, used nanofillers, and nanocomposite processing and properties. Special attention has been paid to the most recent nanocomposite systems developed by combining alternative copolymerization strategies with specific nanoparticles. Thermal, electrical, biodegradation, and surface properties have been illustrated and correlated with the nanoparticle kind, content, and shape. Finally, cell-polymer (nanocomposite) interactions have been described by reviewing analysis methodologies such as primary and stem cell viability, adhesion, morphology, and differentiation processes.

A Perspective on Polylactic Acid-Based Polymers Use for Nanoparticles Synthesis and Applications

“…In in vivo environment, there is an additional contribution to degradation due to enzymes that cleave ester bonds, such as lipases, cutinases, serine proteases, PHB depolymerase, PCL depolymerase, elastase esterase, proteinase K, and trypsin. This enzymatic degradation is a heterogeneous process since involves only device surface: enzymes are not able to diffuse in the polymer matrix and contribute to surface erosion through ester bonds cleavage (Armentano et al, 2018).…”

A Systematic Experimental and Computational Analysis of Commercially Available Aliphatic Polyesters

“…The main factors that influence degradation kinetics are [15] polymer composition (high content of glycolic acid enhances hydrophilicity and thus hydrolysis), molecular weight (high molecular weight polymers degrade slower), crystallinity (semicrystalline polymers exhibit a slower degradation than amorphous ones), pH, addition of drugs (they can enhance or hinder hydrolysis depending on the specific interactions), plasticizers (they promote water penetration), mechanical stress, sterilization, and the fabrication process. This picture is more complicated in an in vivo environment, due to the contribution of enzymes to the degradation process [16].…”

Insight into Mechanobiology: How Stem Cells Feel Mechanical Forces and Orchestrate Biological Functions

“…The paradigm of regenerative medicine is based on the potential of stem cells to maintain tissue homeostasis by replacing dead cells with newly differentiated progenies and releasing active molecules having a critical role in the regenerative processes (autocrine and paracrine actions) [200,211,250,251]. These biological properties are well-maintained, even when stem cells are transplanted into a host tissue/organ in-vivo (direct transplantation) [211,252,253], or when they are engineered with a therapeutic gene (gene-therapy) [254,255,256,257,258,259,260,261,262,263,264,265,266,267,268,269,270], or when they are combined with biomaterials to generate an ex-vivo tissue (tissue engineering) [240,271,272,273,274,275,276,277,278,279,280,281,282,283,284,285]. A further advance is the recent organ-on-a-chip technology [286], which recapitulate the human physiology through culturing stem cells in a tailored artificial tissue or in a single organ system (e.g., cardiac or lung tissues) [278,287,288,289].…”