Progress and Prospects of Polymer-Based Drug Delivery Systems for Bone Tissue Regeneration

Abstract

Despite the high regenerative capacity of bone tissue, there are some cases where bone repair is insufficient for a complete functional and structural recovery after damage. Current surgical techniques utilize natural and synthetic bone grafts for bone healing, as well as collagen sponges loaded with drugs. However, there are certain disadvantages associated with these techniques in clinical usage. To improve the therapeutic efficacy of bone tissue regeneration, a number of drug delivery systems based on biodegradable natural and synthetic polymers were developed and examined in in vitro and in vivo studies. Recent studies have demonstrated that biodegradable polymers play a key role in the development of innovative drug delivery systems and tissue engineered constructs, which improve the treatment and regeneration of damaged bone tissue. In this review, we discuss the most recent advances in the field of polymer-based drug delivery systems for the promotion of bone tissue regeneration and the physical-chemical modifications of polymers for controlled and sustained release of one or more drugs. In addition, special attention is given to recent developments on polymer nano- and microparticle-based drug delivery systems for bone regeneration.

Nanoformulations for Delivery of Pentacyclic Triterpenoids in Anticancer Therapies

“…Their most desirable features are biocompatibility, biodegradability, non-immunogenicity, and non-toxicity. Natural polymers, like chitosan or alginate, may also be useful in the manufacturing and coating of nanocarriers [ 35 ]. For example, the presence of chitosan on the carrier surface allows for the formation of pH-sensitive systems that can release loaded compounds into acidic environments [ 36 ].…”

“…For example, the presence of chitosan on the carrier surface allows for the formation of pH-sensitive systems that can release loaded compounds into acidic environments [ 36 ]. Synthetic polyesters, like poly-ε-caprolactone (PCL), poly-L-lactide (PLA), and poly(lactic-co-glycolic acid) (PLGA) are biodegradable and biocompatible, so the risk of developing toxicity is significantly reduced [ 35 ]. The use of polymers, the structures of which can be precisely controlled, allows for the obtainment of molecules with specific and desired properties, like sensitivity to chemical (pH, temperature, and redox potential) or physical (light, ultrasounds, and magnetic field) stimuli.…”

Collagen Type I Biomaterials as Scaffolds for Bone Tissue Engineering

“…Therefore, synthetic polymers are frequently used in combination with more bioactive materials, such as collagen. In these cases, the synthetic polymer is commonly used to generate a macroporous backbone in which collagen creates a microporous environment for the cells to nest in and to promote their differentiation [ 121 ].…”

Sinking Our Teeth in Getting Dental Stem Cells to Clinics for Bone Regeneration

“…In the previous sections, it was also shown that different drugs and drug concentrations, respectively, are particularly beneficial, depending on the stage of tissue regeneration. Thus, release materials possessing multiple release mechanisms or materials that release the active ingredient in response to a certain stimulus are the focus of recent research [456][457][458][459][460][461].…”