Advances in enzyme immobilization based on hierarchical porous metal-organic frameworks / 生物工程学报

As an excellent hosting matrices for enzyme immobilization, metal-organic framework (MOFs) provides superior physical and chemical protection for biocatalytic reactions. In recent years, the hierarchical porous metal-organic frameworks (HP-MOFs) have shown great potential in enzyme immobilization due to their flexible structural advantages. To date, a variety of HP-MOFs with intrinsic or defective porous have been developed for the immobilization of enzymes. The catalytic activity, stability and reusability of enzyme@HP-MOFs composites are significantly enhanced. This review systematically summarized the strategies for developing enzyme@HP-MOFs composites. In addition, the latest applications of enzyme@HP-MOFs composites in catalytic synthesis, biosensing and biomedicine were described. Moreover, the challenges and opportunities in this field were discussed and envisioned.

Advances in anti-adversity of biological composites based on metal-organic frameworks / 生物工程学报

Metal-organic frameworks (MOFs) are formed by self-assembly of metal ions or clusters with organic ligands, and are widely used in the fields of catalysis, sensing, energy and biomedicine. Recently, biological composites based on MOFs have attracted increasing attention. MOFs can be used as a platform for encapsulating bioactive substances due to the advantages such as large pore capacity, large specific surface area and diverse structure composition. These features can protect bioactive substances from adverse conditions, e.g. high temperature, high pressure, and organic solvents, thus improving the anti-adversity of bioactive substances. This review summarizes the advances of using MOFs as protective coatings to improve the anti-adversity of different bioactive substances, and introduces the synthesis strategy of MOFs-based biological composites, with the aim to promote the practical application of MOFs-based biological composites.

Synthesis of (S)-4-fluorophenylglycine by using immobilized amidase based on metal-organic framework / 生物工程学报

A stable Zr-based metal-organic framework (MOF, UiO-66-NH2) synthesized via micro-water solvothermal method was used to immobilize amidase by using the glutaraldehyde crosslinking method. The effect of immoblization conditions on enzyme immoblization efficiency was studied. An activity recovery rate of 86.4% and an enzyme loading of 115.3 mg/g were achieved under the optimal conditions: glutaraldehyde concentration of 1.0%, cross-linking time of 180 min, and the weight ratio of MOF to enzyme of 8:1. The optimal temperature and optimal pH of the immobilized amidase were determined to be 40 °C and 9.0, respectively, and the Km, Vmax and kcat of the immoblized amidase were 58.32 mmol/L, 16.23 μmol/(min·mg), and 1 670 s⁻¹, respectively. The immobilized enzyme was used for (S)-4-fluorophenylglycine synthesis and the optimal reaction conditions were 300 mmol/L of N-phenylacetyl-4-fluorophenylglycine, 10 g/L of immobilized enzyme loading, and reacting for 180 min at pH 9.0 and 40 °C. A conversion rate of 49.9% was achieved under the optimal conditions, and the conversion rate can be increased to 99.9% under the conditions of enantiomeric excess. The immobilized enzyme can be repeatedly used, 95.8% of its original activity can be retained after 20 cycles.

Outcome of adjustable suspensory fixation for femoral graft in acl reconstruction

Background: The incidence of torn anterior cruciate ligament (ACL) has greatly increased, with today's increasing enthusiasm for sports activities. As a result, reconstruction of the torn anterior cruciate ligament became a common surgical procedure in orthopaedic surgery. Objective: To evaluate short term clinical outcome of adjustable suspensory fixation for femoral graft in ACL reconstruction. Methods: All patients treated for ACL reconstruction with an ipsilateral hamstring between March 2017 and March 2018 were evaluated. Subjects were assigned to TightRope™ (TR) femoral fixation. All patients were evaluated with the Lachman test, pivot-shift test, 2000 International Knee Documentation Committee (IKDC) knee examination. The subjective evaluation was performed using the Lysholm knee score. CT examination was performed to evaluate femoral and tibial tunnels enlargement at four different levels. All patients were assessed at a 12 month follow-up visit. Power analysis was performed a priori in accordance with the femoral and tibial tunnels enlargement values from the CT scans. Results: The group was homogenous at baseline with regard to age, gender, BMI, dominance and disease duration. At the final follow-up, no statistically significant differences were found according to subjective and objective clinical outcome measures. According to the femoral tunnel enlargement, no statistically significant difference was found between tunnel at operation and 12 months later. Conclusion: In transtibial ACL reconstruction, the use of adjustable-loop length device products, on the femoral side, led to better clinical and radiological results

Facile Synthesis of the Magnetic Metal Organic Framework Fe3O4@UiO-66-NH2 for Separation of Strontium / 生物医学与环境科学（英文）

A magnetic metal organic framework (MMOF) was synthesized and used to separate Sr2+ in aqueous solution. The shape and structure of prepared Fe3O4@UiO-66-NH2 were characterized, and the absorbed concentration of strontium was determined through inductively coupled plasma mass spectrometry. The results indicated that Fe3O4 and UiO-66-NH2 combined through chemical bonding. The experimental adsorption results for separation of Sr2+ in aqueous solution indicated that the adsorption of Sr2+ to Fe3O4@UiO-66-NH2 increased drastically from pH 11 to pH 13. The adsorption isotherm model indicated that the adsorption of Sr2+ conformed to the Freundlich isotherm model (R2 = 0.9919). The MMOF thus inherited the superior qualities of magnetic composites and metal organic frameworks, and can easily be separated under an external magnetic field. This MMOF thus has potential applications as a magnetic adsorbent for low level radionuclide 90Sr.

Synthesis and anti-myocarditis activity in a multifunctional lanthanide microporous metal-organic framework with 1D helical chain building units

A new microporous lanthanide metal-organic framework, {[Yb(BTB)(H2O) (DEF)2}n (1, DEF=N,N-Diethylformamide), with 1D nano-sized channels has been constructed by bridging helical chain secondary building units with 1,3,5-benzenetrisbenzoic acid (H3BTB) ligand. Structural characterization suggests that this complex crystallizes in the hexagonal space group P6122 and possesses 1D triangular channels with coordinated water molecules pointing to the channel center. In addition, anti-myocarditis properties of compound 1 were evaluated in vivo. The results showed that compound 1 can improve hemodynamic parameters of, and it may be a good therapeutic option for heart failure in the future.

Two novel Mg(II)-based and Zn(II)-based complexes: inhibiting growth of human liver cancer cells

Two new Mg(II)-based and Zn(II)-based coordination polymers, {[Mg3(BTB)(DMA)4](DMA)2}n (1, H3BTB=1,3,5-benzenetrisbenzoic acid, DMA=N,N-dimethylacetamide) and {(H2NMe2)2[Zn3(BTB)2(OH)(Im)](DMF)9(MeOH)7}n (2, Im=imidazole, DMF=N,N-dimethylformamide), have been successfully synthesized and structurally characterized under solvothermal conditions. 1 contains a linear [Mg3(COO)6] cluster that connected by the fully deprotonated BTB3- ligands to give a kgd-type 2D bilayer structure; 2 represents a microporous 3D pillar-layered system based on the binuclear Zn units and pillared Im ligands, which shows a (3,5)-connected hms topological net. In addition, in vitro anticancer activities of compounds 1 and 2 on 4 human liver cancer cells (HB611, HHCC, BEL-7405 and SMMC-7721) were determined.

Synthesis, crystal structure, and anti-breast cancer activity of a novel metal-porphyrinic complex [YK(TCPP)(OH)2·(solvents)x]

A novel heterometallic metal-porphyrinic framework (MPFs) built from Y and K ions as nods and meso-tetra(4-carboxyphenyl)porphyrin as linkers has been successfully synthesized and characterized. The single crystal X-ray diffraction indicated that this complex 1 exhibited a bilayered architecture of the porphyrins, which is seldom seen in MPFs. In addition, in vitro anticancer activity of complex 1 on three human breast cancer cells (BT474, SKBr-3 and ZR-75-30) was further determined.