Integrating soft and hard tissues via interface tissue engineering

Abstract

The enthesis, or interface between bone and soft tissues such as ligament and tendon, is prone to injury and often does not heal, even post surgical intervention. Interface tissue engineering represents an integrative strategy for regenerating the native enthesis by functionally connecting soft and hard tissues and thereby improving clinical outcome. This review focuses on integrative and cell-instructive scaffold designs that target the healing of the two most commonly injured soft tissue-bone junctions: tendon-bone interface (e.g., rotator cuff) and ligament-bone interface (e.g., anterior cruciate ligament). The inherent connectivity between soft and hard tissues is instrumental for musculoskeletal motion and is therefore a key design criterion for soft tissue regeneration. To this end, scaffold design for soft tissue regeneration have progressed from single tissue systems to the emerging focus on pre-integrated and functional composite tissue units. Specifically, a multifaceted, bioinspired approach has been pursued wherein scaffolds are tailored to stimulate relevant cell responses using spatially patterned structural and chemical cues, growth factors, and/or mechanical stimulation. Moreover, current efforts to elucidate the essential scaffold design criteria via strategic biomimicry are emphasized as these will reduce complexity in composite tissue regeneration and ease the related burden for clinical translation. These innovative studies underscore the clinical relevance of engineering connective tissue integration and have broader impact in the formation of complex tissues and total joint regeneration. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1069-1077, 2018.

Cellular and Chemical Gradients to Engineer the Meniscus‐to‐Bone Insertion

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Amplifying Bone Marrow Progenitors Expressing α‐Smooth Muscle Actin Produce Zonal Insertion Sites During Tendon‐to‐Bone Repair

“…Surgical repair represents one treatment option to improve function and decrease pain. Despite extensive research aimed at improving surgical outcomes, repair failure remains a common problem . High failure rates may be due to a tendon environment that does not support a prompt, effective healing response .…”

Composite clinoptilolite/PCL‐PEG‐PCL scaffolds for bone regeneration: In vitro and in vivo evaluation

“…This situation could be a result of effective primary contact with blood in the defect zone (Figure ). The initial clot formation, which is brought about by blood contact, leads to formation of cytokine gradient allowing attachment molecules to adhere on the surface of construct to both induce cellular attachment and formation of specialized FT, namely, collagenous matrix (Patel et al, ). Moreover, presence of SB and declining FT demonstrated the starting of complete healing stage (Figure h).…”