Detection and Characterization of In Vitro Payload-Containing Catabolites of Noncleavable Antibody-Drug Conjugates by High-Resolution Mass Spectrometry and Multiple Data Mining Tools.

The formation and accumulation of payload-containing catabolites (PCCs) from a noncleavable antibody-drug conjugate (ADC) in targeted and normal tissues are directly associated with the therapeutic effect and toxicity of the ADC, respectively. Understanding the PCC formation is important for supporting the payload design and facilitating preclinical evaluation of ADCs. However, detection and identification of PCCs of a noncleavable ADC are challenging due to their low concentrations and unknown structures. The main objective of this study was to develop and apply a generic liquid chromatography-high-resolution mass spectrometry (LC-HRMS) method for profiling PCCs in vitro. Noncleavable ADCs, ado-trastuzumab emtansine (T-DM1) and ADC-1, were incubated in liver lysosomes, liver S9, and/or cancer cells followed by data acquisition using LC-HRMS. Profiling PCCs mainly relied on processing LC-HRMS datasets using untargeted precise and thorough background subtraction (PATBS) processing and targeted product ion filtering (PIF). As a result, 12 PCCs of T-DM1 were detected and structurally characterized in human liver lysosomal incubation, a majority of which consisted of 4-[N-maleimidomethyl]cyclohexane-1-carboxylate (MCC)-DM1 and a few amino acids. Additionally, the incubation of ADC-1 in human, rat, and monkey liver S9 and cancer cells generated one major and three very minor PCCs, verifying the payload design. The results demonstrate that PATBS enabled the comprehensive profiling of PCCs regardless of their molecular weights, charge states, and fragmentations. As a complementary tool, PIF detected specific PCCs with superior sensitivity. The combination of the in vitro metabolism systems and the LC-HRMS method is a useful approach to profiling in vitro PCCs of noncleavable ADCs in support of drug discovery programs. SIGNIFICANCE STATEMENT: Profiling in vitro payload-containing catabolites (PCCs) of a noncleavable antibody-drug conjugate (ADC) is important for optimization of the payload design and preclinical evaluation of ADC. However, currently used analytical approaches often fail to quickly provide reliable PCC profiling results. The work introduces a new liquid chromatography high resolution mass spectrometry method for comprehensive and rapid detection and characterization of PCCs released from a noncleavable ADC in liver lysosomes and S9 incubations.

[Efficacy of micro steel plate and Kirschner needle oblique and transverse internal fixation of adjacent metacarpal bone in the treatment of metacarpal diaphyseal oblique fracture].

OBJECTIVE: To compare the clinical efficacy of micro steel plate and Kirschner needle oblique and transverse internal fixation of adjacent metacarpal bone in the treatment of metacarpal diaphyseal oblique fracture. METHODS: Fifty-nine patients with metacarpal diaphyseal oblique fractures admitted between January 2018 and September 2021 were selected as the study subjects and divided into the observation group (29 cases) and the control group (30 cases) based on different internal fixation methods. The observation group was treated with Kirschner wire oblique and transverse internal fixation of adjacent metacarpal bones, while the control group was treated with micro steel plate internal fixation. Postoperative complications, operation time, incision length, fracture healing time, treatment cost, and metacarpophalangeal function were compared between the two groups. RESULTS: No incision or Kirschner wire infections occurred in the 59 patients, except for one in the observation group. No fixation loosening, rupture, or loss of fracture reduction occurred in any of the patients. The operation time and incision length in the observation group were (20.5±4.2) min and (1.6±0.2) cm, respectively, which were significantly shorter than those in the control group (30.8±5.6) min and (4.3±0.8) cm (P<0.05). The treatment cost and fracture healing time in the observation group were (3 804.5±300.8) yuan and (7.2±1.1) weeks, respectively, which were significantly lower than those in the control group (9 906.9±860.6) yuan and (9.3±1.7) weeks (P<0.05). The excellent and good rate of metacarpophalangeal joint function in the observation group was significantly higher than that in the control group at 1, 2, and 3 months after operation (P<0.05), but there was no significant difference between the two groups at 6 months after operation (P>0.05). CONCLUSION: Micro steel plate internal fixation and Kirschner wire oblique and transverse internal fixation of adjacent metacarpal bones are both viable surgical methods for treating metacarpal diaphyseal oblique fractures. However, the latter has the advantages of causing less surgical trauma, shorter operation time, better fracture healing, lower cost of fixation materials, and no need for secondary incision and removal of internal fixation.

Neuroprotective effect of combining tanshinone IIA with low-dose methylprednisolone following acute spinal cord injury in rats.

The present study compared the potential neuroprotective effect of tanshinone IIA (TIIA) monotherapy, methylprednisolone (MP) monotherapy and combined treatment in an adult acute spinal cord injury (ASCI) rat model. The current study used the weight-drop method (Allen's Impactor) in the rat model and the mechanical scratch method in primary spinal cord neuron culture to determine whether the combined treatment was able to reduce the required dosage of MP in the treatment of ASCI to produce a similar or improved therapeutic effect. In vivo male Sprague Dawley rats (n=60) were randomly divided into 5 groups, of which 12 rats were selected for the sham group and T9-T11 laminectomies, leading to ASCI, were performed on 48 of the 60 rats using a 10 g ×25 mm weight-drop at the level of T10 spinal cord. Therefore, the ASCI group (n=12) included the 'laminectomy and weight-drop'. The remaining 36 ASCI model animals were subdivided into 3 groups (n=12 each group): TIIA group (30 mg/kg/day), MP group (30 mg/kg) and combined treatment group (TIIA 30 mg/kg/day + MP 20 mg/kg). Neuronal function following ASCI was evaluated using the Basso Beattie Bresnahan (BBB) locomotor rating scale. Levels of the anti-apoptotic factor B-cell lymphoma-2 (Bcl-2), the pro-apoptotic factors Bcl-2 associated protein X (Bax) and caspase-3, and the inflammatory associated factor nuclear factor-κB, were analyzed by western blot analysis. Immunohistochemistry was used to detect caspase-3. To investigate the underlying mechanism, the anti-oxidative effect of combination TIIA and MP treatment was assessed by measuring the activity of malondialdehyde (MDA) and superoxide dismutase (SOD) in ASCI. In agreement with the experiment in vivo, primary neurons were prepared from the spinal cord of one-day-old Sprague-Dawley rats' and co-cultured with astrocytes from the brain cortex. The injury of neurons was induced by mechanical scratch and levels of apoptosis factors were analyzed by western blot analysis. The results of the current study indicated that injured animals in the combined treatment group exhibited a significant increase in BBB scores (P<0.05). TIIA + MP combined treatment and MP treatment was observed to reduce the expression of pro-apoptotic factors and promote neuron survival in vivo and in vitro. Combined treatment may promote neuroprotection through reduced apoptosis and inflammation caused by ASCI, similar to MP alone. Combined treatment reversed the decrease of SOD and the increase of MDA level caused by ASCI. In addition, combined treatment decreased the expression of caspase-3 in the neurons following ASCI in rats, as indicated by immunofluorescence double labeling. Overall, the present study indicates that the combined treatment of TIIA and MP may protect the neurons by stimulating the rapid initiation of neuroprotection following ASCI and reduce the dosage of MP in the treatment of ASCI required to produce the same or improved neuroprotective effects in vivo and in vitro.

A mild and catalyst-free conversion of solid phase benzylidenemalononitrile/benzylidenemalonate to N-benzylidene-amine and its application for fluorescence detection of primary alkyl amine vapor.

A new rapid and catalyst-free solid/vapor reaction between benzylidenemalonate/benzylidenemalononitrile and primary alkyl amines was found. With these as sensory units of fluorescent polymers, probes for primary amine vapor with high sensitivity and selectivity were developed.

A highly efficient fluorescent sensor of explosive peroxide vapor via ZnO nanorod array catalyzed deboronation of pyrenyl borate.

A new strategy capable of detecting explosive peroxide vapor via deboronation reaction induced fluorescence quenching has been developed. Using ordered assembly arrays of ZnO nanorods as catalyzing substrates, the deboronation reaction was 42 times faster than that on quartz substrates, which resulted in a very fast response and high sensitivity.

Sensitivity gains in chemosensing by optical and structural modulation of ordered assembly arrays of ZnO nanorods.

Nanomaterials and -structures have attracted much attention owing to their applications to ultrasensitive nanodevices. In this work, ordered assembly arrays of ZnO nanorods have been hydrothermally fabricated and used as optical substrates of fluorescence sensors for toxic vapors. The unique fastigiate nanorod assembly combines merits of single fibers and clusters, possessing identical orientation, large surface-to-volume ratio, evanescent transmission, and evanescent coupling. As coated on the assembly arrays, different sensing materials all generated amplified spontaneous emission (ASE) action such that the fluorescence intensity of the narrowed spectrum was 52.4-fold enhanced. Results of sensing experiments indicate that sensors based on the assembly arrays displayed 100% elevated normalized quenching rate and several times longer full-load time compared with reference sensors. This work provides a facile method to fabricate secondary structures of 1D rigid material and presents a new way to design highly sensitive optic sensors. Furthermore, evanescent excitation caused ASE action of fluorescent organics, and the correlative sensitivity gain is of interest in both theoretical research and the applications field.

Conjugated polymer-titania nanoparticle hybrid films: random lasing action and ultrasensitive detection of explosive vapors.

We have first demonstrated that a random laser action generated by a hybrid film composed of a semiconducting organic polymer (SOP) and TiO(2) nanoparticles can be used to detect 2,4,6-trinitrotoluene (TNT) vapors. The hybrid film was fabricated by spin-casting SOP solution dispersed with nanosized TiO(2) particles on quartz glass. The SOP in the hybrid film functioned as both the gain medium and the sensory transducer. A random lasing action was observed with a certain pump power when the size (diameter of 50 nm) and concentration (8.9 x 10(12)/cm(3)) of TiO(2) nanoparticles were optimized. Measurements of fluorescence quenching behavior of the hybrid film in TNT vapor atmosphere (10 ppb) showed that attenuated lasing in optically pumped hybrid film displayed a sensitivity to vapors of explosives more than 20 times higher than was observed from spontaneous emission. This phenomenon has been explained with the four-level laser model. Since the sensory transducer used in the hybrid polymer/nanoparticles system could be replaced by other functional materials, the concept developed could be extended to more general domains of chemical or environment detection.

Turn on fluorescence sensing of vapor phase electron donating amines via tetraphenylporphyrin or metallophenylporphrin doped polyfluorene.

A sensitive, selective, reversible, and easy performance way of detecting electron donating volatile amines such as abused drug methamphetamine (MAPA) has been developed.