Current Progress in Tendon and Ligament Tissue Engineering

Abstract

Background: Tendon and ligament injuries accounted for 30% of all musculoskeletal consultations with 4 million new incidences worldwide each year and thus imposed a significant burden to the society and the economy. Damaged tendon and ligament can severely affect the normal body movement and might lead to many complications if not treated promptly and adequately. Current conventional treatment through surgical repair and tissue graft are ineffective with a high rate of recurrence.

Methods: In this review, we first discussed the anatomy, physiology and pathophysiology of tendon and ligament injuries and its current treatment. Secondly, we explored the current role of tendon and ligament tissue engineering, describing its recent advances. After that, we also described stem cell and cell secreted product approaches in tendon and ligament injuries. Lastly, we examined the role of the bioreactor and mechanical loading in in vitro maturation of engineered tendon and ligament.

Results: Tissue engineering offers various alternative ways of treatment from biological tissue constructs to stem cell therapy and cell secreted products. Bioreactor with mechanical stimulation is instrumental in preparing mature engineered tendon and ligament substitutes in vitro.

Conclusions: Tissue engineering showed great promise in replacing the damaged tendon and ligament. However, more study is needed to develop ideal engineered tendon and ligament.

Keywords: Bioreactor; Exosomes; Ligament; Stem cell; Tendon; Tissue engineering.

Fig. 1

Ligament structure. (Reproduced from Ref. [190] with permission from Springer Nature)

Fig. 2

Tendon structure. (Reproduced from Ref. [191])

Fig. 3

Histology of tendon and ligament. A, B The collagen fibers of tendon and ligament are highly aligned. (Reproduced from Ref. [192] with permission from Springer Nature and Ref. [193])

Fig. 4

Stress–strain curve. (Reproduced from Ref. [30])

Fig. 5

Preparation of engineered tendon/ligament

Fig. 6

Schematic diagram of electrospinning equipment. (Reproduced from Ref. [71] with permission from Springer Nature)

Fig. 7

Electrospun polycaprolactone nanofibers

Fig. 8

Communication between the donor cells and recipient cells via exosomes. Exosomes can be up-taken by the neighbouring cells via endocytosis, receptor-ligand interaction and membrane fusion. (Reproduced from Ref. [194] with permission from Elsevier)

Fig. 9

Preparation of platelet-rich plasma