3D Printing of Polylactic Acid Scaffolds for Tissue Engineering

Three-dimensional printing of polylactic acid (PLA) scaffolds has become a cornerstone technology in tissue engineering, enabling the fabrication of bespoke, bioresorbable constructs that mimic native extracellular matrix architecture. PLA’s thermoplastic nature and biodegradability allow the use of fused deposition modelling (FDM) to produce interconnected porous structures with controlled pore size, geometry and interconnectivity. These parameters are tuned to balance mechanical strength with mass transport of oxygen, nutrients and waste, while guiding cell adhesion, proliferation and differentiation. Composite strategies incorporate ceramics such as hydroxyapatite or bioactive glass to enhance osteoconductivity, neutralise acidic degradation by-products and supply ionic cues for bone regeneration. Advances in filament formulation, printer resolution and scaffold design software now permit gradient porosities, patient-specific morphologies and multi-material deposition. In vitro studies demonstrate that optimised PLA-based constructs support mesenchymal stem cell osteogenesis without exogenous growth factors, whereas in vivo experiments confirm biocompatibility, gradual resorption and new tissue ingrowth in critical-sized defects. This synergy of materials science, additive manufacturing and cell biology positions PLA scaffolds as promising platforms for regenerative therapies across orthopaedics, craniofacial reconstruction and soft-tissue repair.

Research from Nature Portfolio

Recent studies have developed porous PLA/hydroxyapatite composites printed by FDM with high ceramic content to match the mechanical properties of trabecular bone. Incorporation of hydroxyapatite above 20 wt % not only neutralises acidification during PLA degradation but also releases calcium and phosphate ions that promote osteogenic differentiation of human mesenchymal stem cells in the absence of classical osteogenic supplements. Importantly, these composite scaffolds exhibit immunological inertness in vitro, showing no activation of dendritic cells or pro-inflammatory cytokine expression. The work highlights how material composition and printing parameters can be co-optimised to produce scaffolds that are both mechanically competent and bioactive, paving the way for translational bone repair applications.

3D Printing of Polylactic Acid Scaffolds for Tissue Engineering publication trend

The graph below shows the total number of articles in 3d printing of polylactic acid scaffolds for tissue engineering across all publications each year (not limited to Nature Index journals).

Technical terms

Polylactic acid (PLA): A biodegradable thermoplastic polyester derived from renewable resources, widely used for scaffold fabrication.
Fused deposition modelling (FDM): An additive manufacturing technique that extrudes molten polymer layer by layer to build three-dimensional structures.
Hydroxyapatite (HA): A calcium phosphate ceramic resembling bone mineral, often incorporated to confer osteoconductivity and buffer acidic degradation.
Porosity: The fraction of void space within a scaffold, crucial for fluid transport, cell migration and vascularisation.
Osteogenic differentiation: The process by which stem or progenitor cells develop into bone-forming osteoblasts under specific biochemical and mechanical cues.

References

1. Three dimensional printed macroporous polylactic acid/hydroxyapatite composite scaffolds for promoting bone formation in a critical-size rat calvarial defect model. Science and Technology of Advanced Materials (2016).
2. PLA/Hydroxyapatite scaffolds exhibit in vitro immunological inertness and promote robust osteogenic differentiation of human mesenchymal stem cells without osteogenic stimuli. Scientific Reports (2022).
3. Polymer-Bioactive Glass Composite Filaments for 3D Scaffold Manufacturing by Fused Deposition Modeling: Fabrication and Characterization. Frontiers in Bioengineering and Biotechnology (2020).
4. Fabrication and properties of PLA/nano-HA composite scaffolds with balanced mechanical properties and biological functions for bone tissue engineering application. Nanotechnology Reviews (2021).
5. The Effect of PCL Addition on 3D-Printable PLA/HA Composite Filaments for the Treatment of Bone Defects. Polymers (2022).