Pectin-Based Injectable Biomaterials for Bone Tissue Engineering

Abstract

A variety of natural polymers and proteins are considered to be 3D cell culture structures able to mimic the extracellular matrix (ECM) to promote bone tissue regeneration. Pectin, a natural polysaccharide extracted from the plant cell walls and having a chemical structure similar to alginate, provides interesting properties as artificial ECM. In this work, for the first time, pectin, modified with an RGD-containing oligopeptide or not, is used as an ECM alternative to immobilize cells for bone tissue regeneration. The viability, metabolic activity, morphology, and osteogenic differentiation of immobilized MC3T3-E1 preosteoblats demonstrate the potential of this polysaccharide to keep immobilized cells viable and differentiating. Preosteoblasts immobilized in both types of pectin microspheres maintained a constant viability up to 29 days and were able to differentiate. The grafting of the RGD peptide on pectin backbone induced improved cell adhesion and proliferation within the microspheres. Furthermore, not only did cells grow inside but also they were able to spread out from the microspheres and to organize themselves in 3D structures producing a mineralized extracellular matrix. These promising results suggest that pectin can be proposed as an injectable cell vehicle for bone tissue regeneration.

Biofunctionalized pectin hydrogels as 3D cellular microenvironments

“…8,16,17 In tissue engineering and regenerative medicine applications there were just a few studies performed using pectin gels. [18][19][20][21][22] Our group 18,19 has previously explored the external gelation of pectin with CaCl 2 to obtain microspheres for the encapsulation of MC3T3 pre-osteoblast cells, which maintained a constant viability up to 29 days and were able to differentiate. Jahromi et al 22 embedded rat bone marrow stromal cells within citrus pectin hydrogels crosslinked by diffusion with CaCl 2 , within which cells were able to differentiate under osteogenic conditions.…”

History and Applications of Hydrogels

“…To overcome this limitation, it is considered important to develop pulp regeneration therapy as well as clarify the mechanisms of pulp wound healing. Pulp wound healing and regeneration have common processes, and results of a number of studies have indicated that pulp wound healing consists of initial inductions of apoptosis of damaged pulp cells [134],followed by reactionary dentinogenesis by surviving odontoblasts and reparative dentinogenesis by odontoblast-like cells [150,151]. Reactionary or reparative dentin is formed toward the residual dental pulp, however, not in the area in which the dentin-pulp complex has been lost.…”

Living Cell Factories ‐ Electrosprayed Microcapsules and Microcarriers for Minimally Invasive Delivery

“…Many natural polymers including alginate [20] , agarose [21] , atelocollagen [22] , fibrin [23] , collagen [24] , chitosan [25] , and pectin [26] resulting in a gel structure [20,27] . Alginates are among the most frequently employed biomaterials for encapsulation due to their abundance, convenient gelling properties and high biocompatibility [28] .…”

“…It is a widely available bioactive polymer and FDA approved which may emphasise its translatability. Its use as a single material or in combination with other materials in carrier and capsule systems may allow for an improved injectable formulation [26] .…”