3D printing of cell-delivery scaffolds for tissue regeneration Jianmin Xue and others

Tissue engineering strategy that combine biomaterials with living cells has shown special advantages in tissue regeneration and promoted the development of regenerative medicine.In particular,the rising of 3D printing technology further enriched the structural design and composition of tissue engineering scaffolds,which also provided convenience for cell loading and cell delivery of living cells.In this review,two types of cell-delivery scaffolds for tissue regeneration,including 3D printed scaffolds with subsequent cell-seeding and 3D cells bioprinted scaffolds,are mainly reviewed.We devote a major part to present and discuss the recent advances of two 3D printed cell-delivery scaffolds in regeneration of various tissues,involving bone,cartilage,skin tissues etc.Although two types of 3D printed cell-delivery scaffolds have some shortcomings,they do have generally facilitated the exploration of tissue engineering scaffolds in multiple tissue regeneration.It is expected that 3D printed cell-delivery scaffolds will be further explored in function mechanism of seeding cells in vivo,precise mimicking of complex tissues and even organ reconstruction under the cooperation of multiple fields in future.

Bioinspired laminated bioceramics with high toughness for bone tissue engineering

For the research of biomaterials in bone tissue engineering,it is still a challenge to fabricate bioceramics that overcome brittleness whilemaintaining the great biological performance.Here,inspired by the toughness of naturalmaterials with hierarchical laminated structure,we presented a directional assembly-sintering approach to fabricate laminated MXene/calcium silicate-based(L-M/CS)bioceramics.Benefiting from the orderly laminated structure,the LM/CS bioceramics exhibited significantly enhanced toughness(2.23MPa·m^(1/2))and high flexural strength(145MPa),which were close to the mechanical properties of cortical bone.Furthermore,the L-M/CS bioceramics possessed more suitable degradability than traditional CaSiO_(3)bioceramics due to the newly formed CaTiSiO_(5)after sintering.Moreover,the L-M/CS bioceramics showed good biocompatibility and could stimulate the expression of osteogenesisrelated genes.The mechanism of promoting osteogenic differentiation had been shown to be related to theWnt signaling pathway.This work not only fabricated calciumsilicate-based bioceramics with excellentmechanical and biological properties for bone tissue engineering but also provided a strategy for the combination of bionics and bioceramics.