(1) Abstract: 

This review evaluates silk fibroin (SF)/polylactic acid (PLA) composite scaffolds as a complementary materials platform for bone and interface tissue regeneration. SF contributes cell-interactive chemistry, hydrophilicity, and enzymatic resorption, whereas PLA provides processability, stiffness, and prolonged structural support. The review compares fabrication methods and relates composition, fiber architecture, interfacial bonding, and degradation to mechanotransduction, osteogenesis, angiogenesis, and macrophage responses, while highlighting evidence gaps and standardization needs.

(2) Background: 

Repair of bone, ligament, tendon, and osteochondral defects remains challenging because existing grafts rarely satisfy mechanical, biological, and degradation requirements simultaneously. Bone tissue engineering requires scaffolds with structural support, cell-interactive cues, and controllable degradation. SF and PLA are complementary, but each has limitations when used alone; composite design must balance structural support and bioactivity at the interfacial and system levels.

(3) Main Content: 

The review summarizes SF sources, structure, biocompatibility, degradation, mechanics, and osteoconductive activity; PLA degradation behavior, mechanical and physicochemical properties, and modification strategies; and composite balancing of stiffness versus toughness, degradation rate versus mechanical integrity, and inertness versus bioactivity. It covers electrospinning, 3D printing, injection/pouring moulding, and other routes, and assesses functional performance in load-bearing bone, tendon/ligament, and osteochondral repair.

(4) Study Design: 

This is a review study. The authors integrate material chemistry, processing methods, scaffold architecture, biological mechanisms, and translational evidence, compare fabrication strategies, and relate composition, fiber architecture, interfacial bonding, and degradation to mechanotransduction, osteogenesis, angiogenesis, and macrophage responses. They distinguish descriptive in vitro findings from in vivo evidence and manufacturing/regulatory considerations, emphasizing that stronger cell responses alone do not establish application readiness.

(5) Results: 

SF/PLA composite scaffolds can achieve structure-mechanics-biology synergy. PLA provides stiffness and structural persistence, while SF contributes toughness, hydrophilicity, and cell-recognition cues. SF degrades enzymatically near neutral pH and may buffer acidic PLA hydrolysis products. Composite scaffolds may influence integrin/FAK/MAPK osteogenic signaling, YAP/TAZ mechanotransduction, and macrophage M1-to-M2 polarization. Different fabrication methods yield nanofibers, patient-specific macropores, or scalable bulk composites, but evidence remains dominated by in vitro and small-animal studies, with insufficient standardized manufacturing and long-term safety evaluation.

(6) Future Directions: 

Future work should prioritize standardized manufacturing and reporting, mechanical testing matched to target tissues, large-animal validation, and long-term immune and degradation evaluation. Artificial intelligence can assist optimization of composition, porosity, fiber alignment, and processing parameters; pH/enzyme-responsive, shape-memory, and thermosensitive scaffolds may enable on-demand delivery; dynamic microenvironment modulation and immunomodulatory strategies warrant further study. Integrated sensing and closed-loop therapeutic systems remain early-stage and require validation of stability, release behavior, biocompatibility, and manufacturing compatibility.

We provide full-process services for various material designs (including highly innovative scheme design, preparation, characterization, in vitro and in vivo validation (cell/animal experiments), etc.): a postdoctoral team (with multiple high-impact publications in Zone 1 journals) can meet all kinds of tricky and challenging requirements, including hydrogels / drug delivery / nanomaterials / polymers / liposomes / microneedle drug delivery, etc. We can assist with project design / NSFC grant applications / publication of high-impact Zone 1 and Zone 2 papers in journals such as AFM, SCI, AM, etc. Welcome to consult 👇️
17768014569 (Senior Engineer Gao)
17761925168 (Engineer Zhang)
18013729810 (Engineer Yang)