Light-mediated intracellular polymerization.

The synthesis of synthetic intracellular polymers offers groundbreaking possibilities in cellular biology and medical research, allowing for novel experiments in drug delivery, bioimaging and targeted cancer therapies. These macromolecules, composed of biocompatible monomers, are pivotal in manipulating cellular functions and pathways due to their bioavailability, cytocompatibility and distinct chemical properties. This protocol details two innovative methods for intracellular polymerization. The first one uses 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (Irgacure 2959) as a photoinitiator for free radical polymerization under UV light (365 nm, 5 mW/cm2). The second method employs photoinduced electron transfer-reversible addition-fragmentation chain-transfer polymerization with visible light (470 nm, 100 mW/cm2). We further elaborate on isolating these intracellular polymers by streptavidin/biotin interaction or immobilized metal ion affinity chromatography for polymers tagged with biotin or histidine. The entire process, from polymerization to isolation, takes ~48 h. Moreover, the intracellular polymers thus generated demonstrate significant potential in enhancing actin polymerization, in bioimaging applications and as a novel avenue in cancer treatment strategies. The protocol extends to animal models, providing a comprehensive approach from cellular to systemic applications. Users are advised to have a basic understanding of organic synthesis and cell biology techniques.

Ultrasound-responsive glycopolymer micelles for targeted dual drug delivery in cancer therapy.

Controlled drug release of nanoparticles was achieved by irreversibly disrupting polymer micelles through high-intensity focused ultrasound (HIFU) induction. An ultrasound-responsive block copolymer was synthesized, comprising an end-functional Eosin Y fluorophore, 2-tetrahydropyranyl acrylate (THPA), and acrylate mannose (MAN). The block copolymer was then self-assembled to produce micelles. The chemotherapy drug dasatinib (DAS) and the sonodynamic therapy agent methylene blue (MB) were encapsulated by the self-assembly of the block copolymer. This targeted nanoparticle enables sonodynamic therapy through high-intensity focused ultrasound while triggering nanoparticle disassembly for controlled drug release. The ultrasound-mediated, non-invasive strategy provides external spatiotemporal control for targeted tumour treatment.

The Application of Artificial-Intelligence-Assisted Dental Age Assessment in Children with Growth Delay.

BACKGROUND: This study aimed to reveal the efficacy of the artificial intelligence (AI)-assisted dental age (DA) assessment in identifying the characteristics of growth delay (GD) in children. METHODS: The panoramic films matching the inclusion criteria were collected for the AI model training to establish the population-based DA standard. Subsequently, the DA of the validation dataset of the healthy children and the images of the GD children were assessed by both the conventional methods and the AI-assisted standards. The efficacy of all the studied modalities was compared by the paired sample t-test. RESULTS: The AI-assisted standards can provide much more accurate chronological age (CA) predictions with mean errors of less than 0.05 years, while the traditional methods presented overestimated results in both genders. For the GD children, the convolutional neural network (CNN) revealed the delayed DA in GD children of both genders, while the machine learning models presented so only in the GD boys. CONCLUSION: The AI-assisted DA assessments help overcome the long-standing populational limitation observed in traditional methods. The image feature extraction of the CNN models provided the best efficacy to reveal the nature of delayed DA in GD children of both genders.

Opportunities and challenges for co-delivery nanomedicines based on combination of phytochemicals with chemotherapeutic drugs in cancer treatment.

The therapeutic limitations such as insufficient efficacy, drug resistance, metastasis, and undesirable side effects are frequently caused by the long duration monotherapy based on chemotherapeutic drugs. multiple combinational anticancer strategies such as nucleic acids combined with chemotherapeutic agents, chemotherapeutic combinations, chemotherapy and tumor immunotherapy combinations have been embraced, holding great promise to counter these limitations, while still taking including some potential risks. Nowadays, an increasing number of research has manifested the anticancer effects of phytochemicals mediated by modulating cancer cellular events directly as well as the tumor microenvironment. Specifically, these natural compounds exhibited suppression of cancer cell proliferation, apoptosis, migration and invasion of cancer cells, P-glycoprotein inhibition, decreasing vascularization and activation of tumor immunosuppression. Due to the low toxicity and multiple modulation pathways of these phytochemicals, the combination of chemotherapeutic agents with natural compounds acts as a novel approach to cancer therapy to increase the efficiency of cancer treatments as well as reduce the adverse consequences. In order to achieve the maximized combination advantages of small-molecule chemotherapeutic drugs and natural compounds, a variety of functional nano-scaled drug delivery systems, such as liposomes, host-guest supramolecules, supramolecules, dendrimers, micelles and inorganic systems have been developed for dual/multiple drug co-delivery. These co-delivery nanomedicines can improve pharmacokinetic behavior, tumor accumulation capacity, and achieve tumor site-targeting delivery. In that way, the improved antitumor effects through multiple-target therapy and reduced side effects by decreasing dose can be implemented. Here, we present the synergistic anticancer outcomes and the related mechanisms of the combination of phytochemicals with small-molecule anticancer drugs. We also focus on illustrating the design concept, and action mechanisms of nanosystems with co-delivery of drugs to synergistically improve anticancer efficacy. In addition, the challenges and prospects of how these insights can be translated into clinical benefits are discussed.

Isolation and identification of new chemical constituents from Chinese chive (Allium tuberosum) and toxicological evaluation of raw and cooked Chinese chive.

Chinese chive (jiu cai) is a popular vegetable in China and has a unique flavour and aroma. The molecular basis of the characteristic fragrance and nutritional properties of Chinese chive has not been previously identified. Sequential extractions in a series of solvents and high-performance liquid chromatography were used to isolate 40 compounds from Chinese chive. The compounds were identified based on high-resolution electrospray ionization mass spectra, 1D and 2D nuclear magnetic resonance techniques, and circular dichroism spectra. Eight novel compounds were identified-four new pyrazines, which have distinctive flavour; one new lignan; and three new flavonoids-together with 32 known compounds. Several of these compounds have potential applications as health-promoting dietary supplements, food additives, or seasonings. Additionally, the volatile organic compounds in fresh and steamed Chinese chive were compared, and the toxicological activity of extracts from fresh and steamed Chinese chive was tested in normal rat liver (IAR20) and kidney (NRK) cells. The results showed that Chinese chive is toxic to liver and kidney cells when fresh, but is safe after heating. This could explain why it is traditional to eat cooked Chinese chive. A possible metabolic rule regarding pyrazines is postulated based on this data, and a human metabolic pathway is suggested for two of the novel compounds which have the highest amount of Chinese chive extracts.

Morphological changes in the midface of Beagle dogs treated by trans-sutural distraction / Cambios morfológicos en la cara media de perros Beagle tratados por distracción trans-sutural

Trans-sutural distraction is a biological process that induces the formation of new bone and changes the position of bone by pulling on growing suture under the action of external forces. Currently, therapy to midfacial hypoplasia treated by trans-sutural distraction has been applied. In this study, Beagle dogs were selected as experimental animals, and a traction device designed by ourselves was applied to Beagle dogs to simulate the treatment process of trans-sutural distraction in human face, so as to provide a basis for the subsequent research on the related mechanism of trans-sutural distraction. The objective is that the animal model can provide the basis for the follow-up study of transsutural distraction. 45 month beagle dogs were randomly divided into two groups 3 in experiment group and 3 in control group. Implant nails were implanted as the bone marker in the bilateral zygomatic temporal suture, zygomandibular maxillary suture and palatine transverse suture in experimental group. The traction of the maxilla was carried out by the external cranial traction frame with canine fossa as bearing point, 800g force each side, elastic traction for 15 days. The control group only implanted the implant nail as the bone marker on both sides of the bone suture. The distance between two implant nails was measured by vernier calipers and X-ray examination, compared with preoperative and postoperative changes. X-ray and cephalometric measurements were used to measure change in the cranial basal angle. HE staining was used to observe the width of the bone seams, the morphology and structure of the cells and the tissue of the new bone under the phase contrast microscope. Then descriptive statistical analysis and t-test between two independent samples are carried out for the measurement data. The experimental group had a good retention of the beagle traction frame. In the experimental group, the maxillaries of dogs were protrudent in the process of traction gradually and the occlusal relationship changed to type II malocclusion. When the traction is 15 days, the coverage distance is about 8~9 mm. Before and after the traction, the distance between landmark points indicated that the spacing between the transverse palatine suture was the largest (experimental group: 5.52±0.19 mm control group 1.31±0.06 mm P<0.05), and zygomaticotemporal suture was the second (experimental group: 3.12±0.15 mm, control group 0.73±0.04 mm, P<0.05), and zygomaticomaxillary suture was less (experimental group: 2.60±0.34 mm, control group 0.53±0.05 mm, P<0.05). The cranial basal angle was no change before and after operation (controlgroup: 32.3±1.3°, experimental group: 33.2±1.1° P>0.05. Histology showed that the collagenous fibers in the suture of the control group were denser and the osteoblasts were visible on the edge of the suture, showing osteogenic activity. The experimental group significantly widened suture (experimental group: 1209.388±42.714 µm, control group 248.276±22.864 µm, P<0.05), the number of fibroblasts increased significantly with loose collagen fiber. The direction of cell and fiber arrangement were parallel to the traction force. There were many small blood vessels and marrow cavities, and the bone trabecula around the bone suture was thin (experimental group: 23.684±3.774 mm, control group: 86.810±9.219 mm, P < 0.05), showing active osteogenic activity. The growing beagle dog can be used to establish a suture traction animal model for experimental study. In the experiment, Kirschner wire was used to penetrate the bottom plane of the piriform hole of the maxilla (about the position of the canine fossa at the back) and the traction direction was basically the same as the growth direction, and the maxilla was basically parallel and moved forward.

La distracción trans-sutural es un proceso biológico que induce la formación de hueso nuevo y cambia la posición del éste al tirar de la sutura en crecimiento bajo la acción de fuerzas externas. Actualmente, se ha aplicado la terapia para la hipoplasia de la cara media tratada por distracción trans-sutural. En este estudio, fueron seleccionados perros Beagle como animales experimentales, y un dispositivo de tracción fue instalado a los perros para simular el proceso de tratamiento de la distracción trans-sutural en el rostro humano. El objetivo fue proporcionar una base para la investigación posterior sobre mecanismos relacionados con la distracción trans-sutural. El modelo animal puede proporcionar la base para este tipo de estudio de seguimiento de la distracción trans-sutural. Perros Beagle de 45 meses de edad se dividieron aleatoriamente en dos grupos: 3 en el grupo experimental y 3 en el grupo control. Los clavos de implante se usaron como marcadores óseos en la sutura temporal cigomática bilateral, la sutura maxilar cigomandibular y en la sutura transversal palatina en el grupo experimental. La tracción del maxilar se realizó mediante el marco de tracción craneal externo con fosa canina como punto de apoyo, 800 g de fuerza a cada lado, tracción elástica durante 15 días. En el grupo control solo se implantó el clavo del implante como marcador óseo en ambos lados de la sutura. La distancia entre dos clavos de implante se midió mediante calibradores de vernier y examen de rayos X, en comparación con los cambios preoperatorios y postoperatorios. Se utilizaron mediciones cefalométricas y de rayos X para medir el cambio en el ángulo basal craneal. La tinción con HE se usó para observar el ancho de las suturas óseas, la morfología y la estructura de las células y el tejido del hueso nuevo bajo el microscopio de contraste de fase. Luego se realizó un análisis estadístico descriptivo y una prueba t entre dos muestras independientes para los datos de medición. El grupo experimental tuvo una buena retención del cuadro de tracción del Beagle. En el grupo experimental, los maxilares de los perros sobresalieron gradualmente en el proceso de tracción y la relación oclusal cambió a maloclusión tipo II. Cuando la tracción era de 15 días, la distancia de cobertura fue de aproximadamente 8 ~ 9 mm. Antes y después de la tracción, la distancia entre los puntos de referencia indicaba que el espacio entre la sutura palatina transversal era más grande (grupo experimental: 5,52 ± 0,19 mm, grupo de control 1,31 ± 0,06 mm, P <0,05), y la sutura cigomáticotemporal fue la segunda. (Grupo experimental: 3,12 ± 0,15 mm, grupo control 0,73 ± 0,04 mm, P <0,05), y la sutura cigomaticomaxilar fue menor (grupo experimental, 2,60 ± 0,34 mm, grupo control 0,53 ± 0,05 mm, P <0,05). El ángulo basal craneal no cambió antes ni después de la operación (grupo control 32,3 ± 1,3, grupo experimental, 33,2 ± 1,1 ° , P> 0,05). La histología mostró que las fibras colágenas en la sutura del grupo control eran más densas y los osteoblastos se observaron en el margen de la sutura, mostrando actividad osteogénica. En el grupo experimental se amplió significativamente la sutura (1209,388 ± 42,714 µm, grupo control 248,276 ± 22,864 µm, P <0,05), el número de fibroblastos aumentó significativamente con fibras colágenas dispersas. La dirección de la disposición de la celda y las fibras era paralela a la fuerza de tracción. Se observó gran cantidad de vasos sanguíneos pequeños, cavidades medulares, y trabéculas óseas alrededor de la sutura ósea (grupo experimental: 23,684 ± 3,774 mm, grupo control: 86,810 ± 9,219 mm, P <0,05), que mostró actividad osteogénica activa. El perro Beagle en crecimiento se puede utilizar para estudios experimentales y así establecer un modelo animal de tracción de sutura. En el proceso, se usó alambre de Kirschner para penetrar en el plano inferior del foramen piriforme del maxilar (aproximadamente en la posición de la fosa canina en la parte posterior) y la dirección de tracción fue básicamente la misma que en el crecimiento.

[Mandibular-driven simultaneous maxillo-mandibular distraction for hemifacial microsomia with rapid prototyping technology].

OBJECTIVE: To explore the clinical application of mandibular-driven simultaneous maxillo-mandihular distraction to correct hemifacial microsomia with rapid prototyping technology. METHODS: The patient' s skull resin model was manufactured with rapid prototyping technology. The osteotomy was designed on skull resin model. According to the preoperative design, the patients underwent Le Fort I osteotomy and mandibular ramus osteotomy. The internal mandible distractor was embedded onto the osteotomy position. The occlusal titanium pin was implanted. Distraction were carried out by mandibular-driven simultaneous maxillo-mandihular distraction 5 days after operation. RESULTS: The distraction in five patients was complete as designed. No infection and dysosteogenesis happened. The longest distance of distraction was 28 mm, and the shortest distance was 16 mm. The facial asymmetry deformity was significantly improved at the end of distraction. The ocelusal plane of patients obviously improved. CONCLUSIONS: Rapid prototyping technology is helpful to design precisely osteotomy before operation. Mandibular-driven simultaneous maxillo-mandibular distraction can correct hemifacial microsomia. It is worth to clinical application.

[Three-dimensional finite element analysis for different directions distraction at midface].

OBJECTIVE: To investigate the biomechanical changes with different directions distraction at midface. METHODS: An anteriorly directed 500 g force was applied to the floor of apertura piriforms in different directions to the occlusal plane. Three-dimensional finite element analysis was used to evaluate the biomechanical change of craniofacial complex. RESULTS: As the force direction was moved downward, the sagittal distraction length of the craniofacial complex decreased and vertical movement changed from upward to downward. The craniofacial complex was moved anteriorly when the downward force was applied about 20-30 degrees to the occlusal plane. The forces could generate the uniform stress distribution in the craniofacial sutures and avoid counterclockwise rotation of the maxilla. CONCLUSIONS: The craniofacial complex can be effectively distracted anteriorly when the downward force is applied to the floor of aperture piriforms in direction of 20-30 degrees to the occlusal plane.

[An ultrastructure study on the palatomaxillary suture of dog expanded by NiTi-SMA].

OBJECTIVE: To explore the ultrastructure of the palate-maxillary sutures under tensile forces by transmission electron microscope (TEM). METHODS: The Suture expanders were made in NiTi-Shape memory alloy (NiTi-SMA). The maximum force was 3.5 N. Fourteen 8-month old mongrel dogs were used in the study. They were divided into three groups, (1) experimental group, (2) control group, (3) sham group. In the experiment and control groups, an 8 mm wide cleft was made by surgery. The suture expanders were fixed onto the palatine bones of the experimental group. The dogs of the experimental group were executed after 3, 7, 14, 28, 56 days of suture expansion. The change of suture tissue was examined by TEM. RESULTS: The cleft of the experiment group were closed at the ninth day of expansion. At the beginning, tissue rupture, exudation, death of fibroblasts, disruption of collagen and tear vessels were seen at the early stage of suture expansion. Then highly active functional manifestations were seen in both osteocytic and fibrocytic populations. At last, normal structure restored. CONCLUSIONS: Cell types and functional condition could be distinguished clearly by TEM. It suggests that the suture expansion should be the process of tissue repair and regeneration. The suture cells response, especially, the osteogenic response were the major factor of increasing suture width.

[Application of thoracic skin flap with multiple blood supply in repair of tissue defects and deformities in jaw and neck].

OBJECTIVE: To explore an appropriate measure to repair tissue defects and deformities in mandibulo-cervical region. METHODS: Eighteen cases with severe tissue defects and deformity in jaw and neck were repaired with thoracic skin flap with multiple blood supply system in our unit from Jan. 2006 to Nov. 2008. Anterior cutaneous branch of transverse cervical artery, intercostal branch of internal thoracic artery and lateral thoracic artery were included in the pedicles. RESULTS: All skin flaps survived, except in one patient in whom a small belb appeared at the distal end of the island flap with anterior cutaneous branch of transverse cervical artery, and it was healed after a few dressing changes. The functions and appearances were satisfactory after 6-month to 2-year follow-up, without showing secondary deformity. CONCLUSIONS: The blood supply of thoracic skin flap is abundant and constant, which is an ideal method for repair of tissue defects and deformities in jaw and neck after taking into account some factors, such as the demand of the patient, general physical condition, and the size of the defect.

[Three-dimensional finite element analysis of craniofacial skeleton protraction at medium position].

OBJECTIVE: The purpose of this study was to investigate the biomechanical changes of midface skeleton protraction at its medium position in the craniofacial complex, using the three-dimensional finite element method (FEM). METHODS: A three-dimensional FEM model was developed from the CT scan images by the technologies of three-dimensional reconstruction, image processing and meshing. The protraction forces were applied to the following locations: the first molar, full maxillary arch, and the floor of aperture piriforms. Biomechanical changes from different position protraction were investigated by means of finite element analyses. RESULTS: Protraction forces at the level of the floor of aperture piriforms produced a more forward movement of the upper maxilla in sagittal direction. Vertical and lateral displacements were less than those in loading with teeth or denture. Compressive stress on the radix nasi decreased obviously in midface skeleton protraction at its medium position. CONCLUSIONS: Compared with traditional orthopedic protraction, midface skeleton protraction at its medium position could advance maxilla en bloc, decrease the counterclockwise rotation of the maxilla, and reduce the constriction of the anterior part of the palate.

[Suppositional sutural construction and application in the three-dimensional finite element model of craniofacial complex].

OBJECTIVE: The purpose of this study was to explore suppositional sutural construction and protraction in the three-dimensional finite element model of craniofacial complex. METHODS: Combining spiral CT scanning technology with the three-dimensional finite element method, three-dimensional FEM model of craniofacial complex was developed for analysis. In the model, craniofacial sutures were constructed through the MSC. Patran program and different mechanical properties of sutures were applied. Under the same loading condition, bone displacements of the maxilla were calculated. RESULTS: A three-dimensional FE model of craniofacial complex, comprising teeth and craniofacial sutures, was developed. The displacement of the skeletal structures with sutures was significantly larger than that without sutures. CONCLUSIONS: The construction of craniofacial sutures in the three-dimensional finite element model of craniofacial complex could improve the accuracy of finite element model, which set up good foundation for biomechanical studies of craniofacial complex.