3D Bioprinting-Based Dopamine-Coupled Flexible Material for Nasal Cartilage Repair

INTRODUCTION

Since 3D printing can be used to design implants according to the specific conditions of patients, it has become an emerging technology in tissue engineering and regenerative medicine. How to improve the mechanical, elastic and adhesion properties of 3D-printed photocrosslinked hydrogels is the focus of cartilage tissue repair and reconstruction research.

MATERIALS AND METHODS

We established a strategy for toughening hydrogels by mixing GelMA-DOPA (GD), which is prepared by coupling dopamine (DA) with GelMA, with HAMA, bacterial cellulose (BC) to produce composite hydrogels (HB-GD). HB-GD hydrogel scaffolds were characterized in vitro by scanning electron microscopy (SEM), Young's modulus, swelling property and rheological property tests. And biocompatibility and chondrogenic ability were tested by live/dead staining, DNA quantitative analysis and immunofluorescence staining. Combined with 3D bioprinting technology, mouse chondrocytes (ADTC5) were added to form a biological chain to construct an in vitro model, and the feasibility of the model for nasal cartilage regeneration was verified by cytology evaluation.

RESULTS

With the increase of GD concentration, the toughness of the composite hydrogel increased (47.0 ± 2.7 kPa (HB-5GD)-158 ± 3.2 kPa (HB-20GD)), and it had excellent swelling properties, rheological properties and printing properties. The HB-GD composite hydrogel promoted the proliferation and differentiation of ATDC5. Cells in 3D printed scaffolds had higher survival rates (> 95%) and better protein expression than the encapsulated cultures.

CONCLUSION

The HB-10GD hydrogel can be made into a porous scaffold with precise shape, good internal pore structure, high mechanical strength and good swelling rate through extrusion 3D printing.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Effects of medical abortion assisted by traditional Chinese medicine: A network meta-analysis of randomized controlled trials

BACKGROUND

To what extent traditional Chinese medicine (TCM) combined with mifepristone and misoprostol is beneficial for improving the complete abortion rate and duration of vaginal bleeding has been a subject of debate in the field of medical abortion.

OBJECTIVE

To assess the evidence regarding the complete abortion rate and duration of vaginal bleeding of medical abortion assisted by different kinds of TCM.

SEARCH STRATEGY

We searched electronic databases such as PubMed, Web of Science and Cochrane Library database, China National Knowledge Internet, Wan fang Database, VIP Database, and China Biology Medicine disc from 2000 to February 15, 2023.

SELECTION CRITERIA

The control group was medical abortion with mifepristone and misoprostol, and the experimental group was medical abortion assisted by TCM.

DATA COLLECTION AND ANALYSIS

Major data extraction included sample size, age, medicine used for abortion, outcome measures. RevMan 5.3 and Stata 15.1 software were used to assess the literature quality and perform network meta-analysis, respectively.

MAIN RESULTS

A total of 73 randomized controlled trials (RCTs) with 11 683 patients and nine kinds of TCM were included in this study. Compared with mifepristone and misoprostol, eight kinds of TCM had statistical significance in improving the complete abortion rate. The effect value of Sancao decoction was 5.86 (95% confidence interval [CI] 2.53-13.58). Seven kinds of TCM shortened the duration of vaginal bleeding. The effect value of comfrey and trichosanthin decoction was -8.75 (95% CI -10.86 to -6.64).

CONCLUSIONS

This network meta-analysis showed that Lenge Zhumo decoction and Sancao decoction could have a large beneficial effect on complete abortion rate in medical abortion during early pregnancy, and comfrey and trichosanthin decoction could be the best TCM for shortening the duration of vaginal bleeding.

A BTO/PVDF/PDMS Piezoelectric Tangential and Normal Force Sensor Inspired by a Wind Chime

There is a growing demand for flexible pressure sensors in environmental monitoring and human-robot interaction robotics. A flexible and susceptible sensor can discriminate multidirectional pressure, thus effectively detecting signals of small environmental changes and providing solutions for personalized medicine. This paper proposes a multidimensional force detection sensor inspired by a wind chime structure with a three-dimensional force structure to detect and analyze normal and shear forces in real time. The force-sensing structure of the sensor consists of an upper and lower membrane on a polydimethylsiloxane substrate and four surrounding cylinders. A piezoelectric hemisphere is made of BTO/PVDF/PDMS composite material. The sensor columns in the wind chime structure surround the piezoelectric layer in the middle. When pressure is applied externally, the sensor columns are connected to the piezoelectric layer with a light touch. The piezoelectric hemisphere generates a voltage signal. Due to the particular structure of the sensor, it can accurately capture multidimensional forces and identify the direction of the external force by analyzing the position of the sensor and the output voltage amplitude. The development of such sensors shows excellent potential for self-powered wearable sensors, human-computer interaction, electronic skin, and soft robotics applications.