Jh. Jang

Effects of Recombinant Dentin Sialoprotein in Dental Pulp Cells

Dentin sialophosphoprotein (DSPP) is critical for dentin mineralization. However, the function of dentin sialoprotein (DSP), the cleaved product of DSPP, remains unclear. This study aimed to investigate the signal transduction pathways and effects of recombinant human DSP (rh-DSP) on proliferation, migration, and odontoblastic differentiation in human dental pulp cells (HDPCs). The exogenous addition of rh-DSP enhanced the proliferation and migration of HDPCs in dose- and time-dependent manners. rh-DSP markedly increased ALP activity, calcium nodule formation, and levels of odontoblastic marker mRNA. rh-DSP increased BMP-2 expression and Smad1/5/8 phosphorylation, which was blocked by the BMP antagonist, noggin. Furthermore, rh-DSP phosphorylated extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), Akt, and IκB-α, and induced the nuclear translocation of the NF-κB p65 subunit. Analysis of these data demonstrates a novel signaling function of rh-DSP for the promotion of growth, migration, and differentiation in HDPCS via the BMP/Smad, JNK, ERK, MAPK, and NF-κB signaling pathways, suggesting that rh-DSP may have therapeutic utility in dentin regeneration or dental pulp tissue engineering.

Advanced Biomatrix Designs for Regenerative Therapy of Periodontal Tissues

Periodontitis is an inflammatory disease that causes loss of the tooth-supporting apparatus, including periodontal ligament, cementum, and alveolar bone. A broad range of treatment options is currently available to restore the structure and function of the periodontal tissues. A regenerative approach, among others, is now considered the most promising paradigm for this purpose, harnessing the unique properties of stem cells. How to make full use of the body’s innate regenerative capacity is thus a key issue. While stem cells and bioactive factors are essential components in the regenerative processes, matrices play pivotal roles in recapitulating stem cell functions and potentiating therapeutic actions of bioactive molecules. Moreover, the positions of appropriate bioactive matrices relative to the injury site may stimulate the innate regenerative stem cell populations, removing the need to deliver cells that have been manipulated outside of the body. In this topical review, we update views on advanced designs of biomatrices—including mimicking of the native extracellular matrix, providing mechanical stimulation, activating cell-driven matrices, and delivering bioactive factors in a controllable manner—which are ultimately useful for the regenerative therapy of periodontal tissues.

A gait-assistive mobile robot based on a body weight support and autonomous path tracking system

With the rising numbers of elderly and disabled people, the demand for welfare services using a robotic system and not involving human effort is likewise increasing. This study deals with a mobile robot system combined with a body weight support (BWS) system for gait rehabilitation. The BWS system was designed via the kinematic analysis of the robots body-lifting characteristics and of the walking guide system that controls the total rehabilitation system integrated in the mobile robot. This mobile platform is operated by utilizing the autonomous guided vehicle driving algorithm. Especially, the method that integrates geometric path tracking and obstacle avoidance for a non-holonomic mobile robot was applied so that the system can be operated in an area where the elderly users are expected to be situated, such as in a public hospital or a rehabilitation centre. The mobile robot follows the path by moving through the turning radius supplied by the pure-pursuit method, one of the existing geometric path-tracking methods. The effectiveness of the proposed method was verified through real experiments that were conducted for path tracking with static and dynamic obstacle avoidance. Finally, through electromyography signal measurement of the subject, the performance of the proposed system in a real operation condition was evaluated.