Electrospining Machine: Immediate implantation of a cellular electrospinning-based microfiber slow-release system to induce osteogenesis in mesenchymal stem cells

Background

Bone plays many important roles in the human body, providing a structural framework for muscles and other tissues, facilitating movement, and protecting internal organs from injury. Large bone defects caused by bone tumors, bone injuries, and other skeletal disorders often do not heal themselves through the body's natural repair mechanisms. Therefore, bone grafts, whether natural or synthetic, are needed to replace diseased or missing bone. While conventional grafting techniques are effective, they can lead to surgical complications and undesirable outcomes. This has driven the rise of tissue engineering solutions, particularly bone tissue engineering, as promising alternatives.

The main point of this paper

Advances in bone tissue engineering:

Bone tissue engineering has achieved good results by combining scaffolds constructed from biomaterials and stem cells, which are osteoinductively implanted in vitro into bone defect sites in animals

Application of electrospinning technology:

Electrospinning technology is used to prepare scaffolds for bone tissue engineering, in which the precursor solution is transformed into fine fibers by a high-voltage electric field, forming a fibrous membrane that mimics the extracellular matrix, providing a favorable environment for cell proliferation and osteogenesis

Limitations of electrospinning with CES technology:

Electrospinning scaffolds suffer from uneven seed cell distribution and poor cell infiltration. Cell electrostatic spinning (CES) technology is capable of producing fibers embedded in living cells, providing immediate implantation conditions

Biomaterial of choice:

Poly (3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB), a polyhydroxyalkanoate derivative, is of interest in bone tissue engineering for its mechanical robustness, biocompatibility and biodegradability

Supplementation of osteogenic induction medium:

ASP, sodium β-glycerophosphate (GP) and dexamethasone (DEX) are essential supplements in osteoblast induction medium and are promotive for osteoblast differentiation in vitro.

Drug slow release system:

Nanofibers prepared with core-shell nozzles can confine the drug in the core layer, which helps to control the initial release of the drug and prolong the release time

P34HB-based microfiber slow-release system: an innovative strategy to promote osteogenic induction of human umbilical cord mesenchymal stem cells in vivo

Technology Application:

Encapsulation of ASP, sodium β-glycerophosphate and DEX in P34HB fibers for sustained osteogenic differentiation using dual nozzle and cytostatic spinning techniques.

Scaffold characterization:

The morphology, characterization, hydrophilicity, mechanical properties and cellular behavior of the scaffolds were studied.

Ectopic osteogenic induction:

The ectopic osteogenic induction of scaffolds was observed by immediate subcutaneous implantation in rabbits.

Scaffold preparation and characterization:

The P34HB microfiber slow-release system was successfully prepared, and the characterization results confirmed that the HUCMSCs and the induction components were uniformly distributed within the scaffold, and the active components were not affected by the chemical reaction.

In vitro testing:

In vitro tests showed long release times for DEX and ASP, and biocompatibility tests highlighted the adaptability of the scaffolds to cell growth.

Osteogenic induction effect:

Alizarin red, type I collagen and osteoblastin (OPN) staining confirmed the potent osteogenic induction of HUCMSCs by the scaffolds

Summarize

In this study, we successfully developed a P(AGD)-CES microfiber sustained-release system using dual nozzles and CES, which can be immediately implanted in vivo without prior in vitro induction. Both in vitro and in vivo experiments demonstrated the potential of this system to promote osteogenic differentiation of HUCMSCs, highlighting its promise as a novel therapeutic tool. Given the biomimetic properties, mechanical robustness, biocompatibility, and sustained-release capability of the P(AGD)-CES system, it offers an innovative approach for the clinical treatment of bone defects. The shortcomings of this study are the lack of in vivo osteogenic marker analysis and in situ osteogenic assessment. Follow-up studies will further improve