Injectable and Crosslinkable PLGA‐Based Microribbons as 3D Macroporous Stem Cell Niche

Abstract

Poly(lactide‐co‐glycolide) (PLGA) has been widely used as a tissue engineering scaffold. However, conventional PLGA scaffolds are not injectable, and do not support direct cell encapsulation, leading to poor cell distribution in 3D. Here, a method for fabricating injectable and intercrosslinkable PLGA microribbon‐based macroporous scaffolds as 3D stem cell niche is reported. PLGA is first fabricated into microribbon‐shape building blocks with tunable width using microcontact printing, then coated with fibrinogen to enhance solubility and injectability using aqueous solution. Upon mixing with thrombin, firbornogen‐coated PLGA microribbons can intercrosslink into 3D scaffolds. When subject to cyclic compression, PLGA microribbon scaffolds exhibit great shock‐absorbing capacity and return to their original shape, while conventional PLGA scaffolds exhibit permanent deformation after one cycle. Using human mesenchymal stem cells (hMSCs) as a model cell type, it is demonstrated that PLGA μRB scaffolds support homogeneous cell encapsulation, and robust cell spreading and proliferation in 3D. After 28 days of culture in osteogenic medium, hMSC‐seeded PLGA μRB scaffolds exhibit an increase in compressive modulus and robust bone formation as shown by staining of alkaline phosphatase, mineralization, and collagen. Together, the results validate PLGA μRBs as a promising injectable, macroporous, non‐hydrogel‐based scaffold for cell delivery and tissue regeneration applications.

Recent Trends in the Development of Bone Regenerative Biomaterials

“…The generated acid has a catalytic effect on degradation with an autocatalytic effect, and these carboxylic acids cause a local acidic microenvironment that is harmful to cell proliferation and bone repair, which can produce a potentially inflammatory reaction. In addition, when such materials are used as bone defect repair materials, it is necessary to composite growth factors, cells, or other materials to improve biological activity to facilitate cell adhesion and proliferation (Yassin et al, 2017;Barati et al, 2020;Bharadwaz and Jayasuriya, 2020). The composite scaffolds composed of degradable synthetic polymers and bioceramics have aroused great interest in many researchers.…”

Recent Advances in Macroporous Hydrogels for Cell Behavior and Tissue Engineering

“…Fibrinogens are important proteins involved in the coagulation process. Coating PLGA microribbon (μRB) with fibrinogen not only improves its injectability and in situ cross-linking, but also further supports the encapsulation and rapid adhesion of hMSCs in hydrogels [ 218 ]. Lectin is a glycoprotein that can agglutinate red blood cells by specifically binding to glycosylated structures on the cell surface.…”

3D printing of bone and cartilage with polymer materials

“…The polylactic acid-glycolic acid copolymer is widely used in medicine, chemistry, industry, and other fields because of its non-toxicity and good biological activity, biocompatibility, and mechanical properties ( Barati et al, 2020 ; Carlier et al, 2021 ). The polylactic acid-glycolic acid copolymer can be degraded by breaking the ester bond, and its degradation products are the same as those of human metabolism ( Jiang et al, 2020b ).…”