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3D bioprinting techniques have enabled the fabrication of irregular large-sized tissue engineering scaffolds. However, complicated customized designs increase the medical burden. Meanwhile, the integrated printing process hinders the cellular uniform distribution and local angiogenesis. A novel approach is introduced to the construction of sizable tissue engineering grafts by employing hydrogel 3D printing for modular bioadhesion assembly, and a poly (ethylene glycol) diacrylate (PEGDA)-gelatin-dopamine (PGD) hydrogel, photosensitive and adhesive, enabling fine microcage module fabrication via DLP 3D printing is developed. The PGD hydrogel printed micocages are flexible, allowing various shapes and cell/tissue fillings for repairing diverse irregular tissue defects. In vivo experiments demonstrate robust vascularization and superior graft survival in nude mice. This assembly strategy based on scalable 3D printed hydrogel microcage module could simplify the construction of tissue with large volume and complex components, offering promise for diverse large tissue defect repairs.
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Hidrogéis , Camundongos Nus , Impressão Tridimensional , Engenharia Tecidual , Alicerces Teciduais , Animais , Camundongos , Engenharia Tecidual/métodos , Hidrogéis/química , Alicerces Teciduais/química , Gelatina/química , Bioimpressão/métodos , Polietilenoglicóis/química , Neovascularização Fisiológica/fisiologia , Dopamina/metabolismo , Regeneração/fisiologia , HumanosRESUMO
Flower development, as the basis for plant seed development, is principally conserved in angiosperms. At present, a number of genes regulating flower organ differentiation have been identified, and an ABCDE model has also been proposed. In contrast, the mechanism that regulates the development of the sterile lemma remains unclear. In this study, we identified and characterized a rice floral organ mutant, M15, in which the sterile lemma transformed into a lemma-like organ. Positional cloning combined with a complementary experiment demonstrated that the mutant phenotype was restored by LONG STERILE LEMMA1/(G1). G1 was expressed constitutively in various tissues, with the highest expression levels detected in the sterile lemma and young panicle. G1 is a nucleus-localized protein and functions as a homomer. Biochemical assays showed that G1 physically interacted with OsMADS1 both in vitro and in vivo. Interestingly, the expression of G1 in M15 decreased, while the expression level of OsMADS1 increased compared with the wild type. We demonstrate that G1 plays a key role in sterile lemma development through cooperating with OsMADS1. The above results have implications for further research on the molecular mechanisms underlying flower development and may have potential applications in crop improvement strategies.
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Circular RNAs (circRNAs) are a member of non-coding RNAs with no ability in encoding proteins and their aberrant dysregulation is observed in cancers. Their closed-loop structure has increased their stability, and they are reliable biomarkers for cancer diagnosis. Urological cancers have been responsible for high mortality and morbidity worldwide, and developing new strategies in their treatment, especially based on gene therapy, is of importance since these malignant diseases do not respond to conventional therapies. In the current review, three important aims are followed. At the first step, the role of circRNAs in increasing or decreasing the progression of urological cancers is discussed, and the double-edged sword function of them is also highlighted. At the second step, the interaction of circRNAs with molecular targets responsible for urological cancer progression is discussed, and their impact on molecular processes such as apoptosis, autophagy, EMT, and MMPs is highlighted. Finally, the use of circRNAs as biomarkers in the diagnosis and prognosis of urological cancer patients is discussed to translate current findings in the clinic for better treatment of patients. Furthermore, since circRNAs can be transferred to tumor via exosomes and the interactions in tumor microenvironment provided by exosomes such as between macrophages and cancer cells is of importance in cancer progression, a separate section has been devoted to the role of exosomal circRNAs in urological tumors.
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Biomarcadores Tumorais , Resistencia a Medicamentos Antineoplásicos , RNA Circular , Neoplasias Urológicas , Humanos , RNA Circular/genética , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Urológicas/genética , Neoplasias Urológicas/patologia , Neoplasias Urológicas/tratamento farmacológico , Neoplasias Urológicas/diagnóstico , Biomarcadores Tumorais/genética , Metástase Neoplásica , AnimaisRESUMO
ZIF-8 may experience ion-responsive degradation in ionic solutions, which will change its initial architecture and restrict its direct biological use. Herein, we report an abnormal phenomenon in which ZIF-8 induces large hydroxyapatite-like crystals when soaked directly in simulated body fluid. These crystals grew rapidly continuously for two weeks, with the volume increasing by over 10 folds. According to Zn2+ release and novel XRD diffraction peak presence, ZIF-8 particles can probably show gradual collapse and became congregate through re-nucleation and competitive coordination. The phenomenon could be found on ZIF-8/PCL composite surface and printed ZIF-8/PCL scaffold surface. ZIF-8 enhanced PCL roughness through changing the surface topography, while obviously improving the in-vivo and in-vitro osteoinductivity and biocompatibility. The pro-biomineralization property can make ZIF-8 also applicable in polylactic acid-based biomaterials. In summary, this study demonstrates that ZIF-8 may play the role of a bioactive additive enabling the surface modification of synthetic polymers, indicating that it can be applied in in-situ bone regeneration.
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Durapatita , Alicerces Teciduais , Durapatita/química , Alicerces Teciduais/química , Materiais Biocompatíveis/química , Osteogênese , Poliésteres/química , Impressão Tridimensional , Engenharia TecidualRESUMO
The left-behind children (LBC), separated from their mother/father or parents for a long period of time, have long been discussed as a subject of concern in China. Existing research has concluded that rural children who did not migrate with parents are subject to emotional risks. In the present study, the purpose is to study the impact of parental migration on early emotional understanding. Purposeful sampling was used to recruit 180 children aged five to six years in rural areas of Guangdong province, including LBC and non-left-behind children (NLBC). Their level of emotional understanding (EU) was assessed by the emotional comprehension test (TEC) adapted to the Chinese context. The results showed that, on the three levels (External, Internal, Reflective) of emotional understanding, LBC aged five- to six- years old scored significantly lower than NLBC as counterparts. On the whole, the emotional comprehension ability of preschool LBC was significantly lower than that of NLBC. However, there were no significant differences within LBC nurtured by single parents, grandparents, and other relatives. This study confirmed that parental migration in early childhood considerably impacted rural LBC's emotional understanding and affectional adjustment, which provided a significant basis for increasing parental care and early childhood companionship in rural areas.
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Emoções , População Rural , Feminino , Humanos , Criança , Pré-Escolar , China , Mães , PrazerRESUMO
There is growing concern about the environmental impact of chemicals and the long-term effects of mechanical weeding, which inhibits weed regrowth. Mechanical-chemical synergy has become an alternative weeding practice. In this paper, the effects of reduced chemical application by mechanical-chemical synergetic weeding on maize growth and yield are studied via synergistic weeding experiments. Experiments were carried out using three chemical reduction ratios (25%, 50%, and 75%) and two chemical applications (full width and only seeding row). The existing inter- and intra-implements were integrated as weeding machinery for full range mechanical weeding. Two indicators (leaf area and dry matter weight) were defined as growth characteristics at the filling and maturity stages. The results show that the leaf area of mechanical-chemical synergistic treatments was larger than those of single mechanical or chemical weeding treatments at the filling stage, but there was no significant difference between the leaf area values of the synergetic treatments (P=0.939). At the filling and maturity stages, the dry matter weight of mechanical-chemical weeding treatments was greater compared to the chemical weeding treatment. At the filling stage, the dry matter weight of the mechanical-chemical synergistic weeding treatments was less than that of the mechanical weeding treatment. In contrast, at the maturity stage, the dry matter weight of mechanical-chemical weeding treatments was greater, indicating that the promotional effect of the mechanical-chemical synergistic model was more pronounced at the later stage of crop growth. Single weeding or non-weeding treatment significantly affected the number of grains per ear (p=0.037) and 1000 grain weight (p=0.019), but it has been observed to have no significant effect on yield (p=0.504). The number of grains per ear, 1000 grain weight, and yield of the mechanical-chemical synergistic treatment were observed to be better than those of the chemical treatment. When compared with the full range of mechanical weeding treatments, only synergistic treatment produced a higher yield. From the perspectives of leaf area and dry matter, yield and its components, at the filling and maturity stage, the effect of mechanical-chemical synergy with 50% chemical reduction is the best recommendation as it reduces the dosage of chemical application, without significantly affecting crop growth and yield.
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Advances in stem cell biology have posed the challenges in revealing the mechanistic themes underlying whole tissues and organs formation during regeneration. The planarian Dugesia japonica is an ideal model organism for the study of regeneration and stem cell biology. However, the genome resources for this species are still limited. Here, we combined single-molecule real-time DNA sequencing platform Pacific Biosciences (PacBio) sequencing, Illumina paired-end sequencing and 10× Genomics linked reads data to obtain the whole-genome sequence of the planarian D. japonica. The final assembled D. japonica genome is 1.13G with contig N50 of 248.44 kb, and scaffold N50 of 652.52 kb. Repeat elements account for 64.92% of the genome, and 12,031 protein coding genes were annotated, of which 10,114 genes had at least one functional annotation, representing 84.07% of the total genes. We present a highly contiguous genome assembly of D. japonica. The D. japonica genome assembly, together with gene annotation and transcriptome data provide a valuable resource to investigate molecular mechanism of planarian and stem cell research.
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Planárias , Animais , Genoma , Genômica , Sequenciamento de Nucleotídeos em Larga Escala , Anotação de Sequência Molecular , Planárias/genéticaRESUMO
The growing transportation risk of hazardous materials (hazmat) is an important threat to public safety. As an efficient and reliable mode of transportation, the multimodal hub-and-spoke transport network helps to achieve economies of scale and reduce costs. Considering the dual goals of risk and cost management of hazmat transportation, a novel optimization model of a multimodal hub-and-spoke network with detour (MHSNWD) for hazmat on the strategic level is designed. It integrates the planning of hub location and route selection based on the risk quantification for different transportation modes. Additionally, a detour strategy is applied, which allows for more than two hub nodes to be selected to form an optimal path between any supply and demand nodes in a hub-and-spoke network. Then, the risk is taken as the main objective and the cost is converted into a budget constraint to solve the model by using CPLEX. Additionally, a numerical study is conducted based on a CAB dataset to find the influence of the number of hubs and budget constraints on the optimization results. In addition, a counterpart model of the multimodal hub-and-spoke network without detour (MHSNOD) is tested to validate the advantages of the proposed model of MHSNWD. The numerical experiment shows that an appropriate increase in the number of hubs and the cost budget can remarkably reduce network risk. Compared with MHSNOD, the optimal result of MHSNWD can achieve a marginal improvement in risk reduction. This work may provide an informative decision-making reference for planning a hazmat transportation network.
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Substâncias Perigosas , Meios de TransporteRESUMO
SUMOylation and ubiquitylation are homologous processes catalyzed by homologous enzymes, and they are involved in nearly all aspects of eukaryotic biology. Planarians, which have the remarkable ability to regenerate their central nervous system (CNS), provide an excellent opportunity to investigate the molecular processes of CNS regeneration in vivo. In this study, we analyzed gene expression profiles during head regeneration with an RNA-seq-based screening approach and found that Djnedd4L and Djubc9 were required for head regeneration in planarians. RNA interference targeting of Djubc9 caused the phospho-H3 mitotic cells to decrease in quantity, or even become absent as a part of the Djubc9 RNAi phenotype, which also showed the collapse of the stem cell lineage along with the reduced expression of epidermal differentiation markers. Furthermore, we found that Djnedd4L RNAi induced increased cell division and promoted the premature differentiation during regeneration. Taken together, our findings show that Djubc9 and Djnedd4L are required for stem cell maintenance in the planarian Dugesia japonica, which helps to elucidate the role of SUMOylation and ubiquitylation in regulating the regeneration process.
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Ubiquitina-Proteína Ligases Nedd4/metabolismo , Planárias/fisiologia , Regeneração , Células-Tronco/fisiologia , Enzimas de Conjugação de Ubiquitina/metabolismo , Animais , Ubiquitina-Proteína Ligases Nedd4/genética , Enzimas de Conjugação de Ubiquitina/genéticaRESUMO
This paper empirically studies the relationship among inclusive finance, industrial structure upgrading and farmers' income, using the panel data of 28 provinces in China from 2006 to 2016.The research finds that inclusive finance can significantly promote the increase of farmers' income. Moreover, the Upgrading of Industry Structure (UIS) is the intermediary mechanism of inclusive finance to promote the increase of farmers' income, and this intermediary mechanism is heterogeneous among farmers with different income levels. Finally, the promotion effect of the UIS on farmers' income is affected by the threshold effect of inclusive finance. Compared with the development level of low inclusive finance, the promotion effect of the UIS on farmers' income is stronger under the development level of high inclusive finance. According to the results of empirical analysis, we suggest that the development strategy of inclusive finance should aim at the industrial development in rural areas, promote the organic connection between farmers and modern agricultural industry, and drive farmers to increase their income through the transformation and upgrading of rural industries.
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Agricultura/economia , Fazendeiros , Organização do Financiamento/economia , Renda , China , HumanosRESUMO
PURPOSE: Gastric cancer is a common tumor type associated with nutritional and immune status. The aim of the current study was to investigate the prognostic value of a preoperative prognostic nutritional index (PNI), composed of nutritional factors and immune factors in elderly patients undergoing gastric cancer surgery. PATIENTS AND METHODS: A total of 454 patients undergoing gastric cancer surgery were divided into two groups based on preoperative PNI scores: ≤45.1 (n = 307) and >45.1 (n = 147). Survival analysis was performed using the Kaplan-Meier method and Log rank tests. Univariate and multivariate analyses were conducted to identify independent prognostic factors using a Cox proportional hazards model. RESULTS: According to the X-tile program, the optimal cutoff value for predicting overall survival (OS) with the PNI was 45.1. The receiver operating characteristic analysis revealed that PNI exhibited 70.6% sensitivity and 56.5% speciï¬city for predicting death during long-term follow-up. The cumulative incidence of postoperative 4-year mortality indicated that the risk of death increased significantly for PNI ≤45.1. In multivariate analysis, preoperative PNI was a significant independent predictor of mortality. In the age-stratified subgroup analysis, preoperative PNI was more sensitive for the old elderly subgroup than for the young elderly subgroup. CONCLUSION: Preoperative PNI is a sensitive and specific prognostic predictor among elderly patients undergoing gastric cancer surgery.
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Surface modification using bioactive molecules is frequently performed to improve the biological properties of medical metal biomaterial titanium (Ti) implants. Developmental evidence suggests that mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) served as potent bioactive component. As a subset of MSC-EV, adipose-derived stem cell-derived extracellular vesicles (ADSC-EVs) could be obtained from abundant adipose tissue. Meanwhile, it possesses multiple regenerative properties and might be used to endow biological activities to medical Ti implant. Here, we present a simple ADSC-EV coating strategy based on physisorption of fibronectin. This ADSC-EV functionalized Ti implants (EV-Ti) revealed enhanced osteoblast compatibility and osteoinductive activity. Cell spreading area of EV-Ti group was 1.62- and 1.48-fold larger than that of Ti group after 6 and 12 h of cell seeding, respectively. Moreover, EV-Ti promoted alkaline phosphatase, collagen 1 and osteocalcin gene expression in osteoblast by 1.51-, 1.68- and 1.82-fold compared with pristine Ti, respectively. Thus, the MSC-EVs modification method reported here provide a clinically translatable strategy to promote the bioactivity of Ti implants.
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The molecular mechanisms responsible for axis establishment during non-embryonic processes remain elusive. The planarian flatworm is an ideal model organism to study body axis polarization and patterning in vivo. Here, we identified a homolog of the TBX2/3 in the planarian Dugesia japonica. RNA interference (RNAi) knockdown of TBX2/3 results in the ectopic formation of protrusions in the midline of the dorsal surface which shows an abnormal expression of midline and ventral cell markers. Additionally, the TBX2/3 RNAi animals also show the duplication of expression of the boundary marker at the lateral edge. Furthermore, TBX2/3 is expressed in muscle cells and co-expressed with bmp4. Inhibition of bone morphogenetic protein (BMP) signaling reduces the expression of TBX2/3 at the midline. These results suggest that TBX2/3 RNAi results in phenotypic characters caused by inhibition of the BMP signal, indicating that TBX2/3 is required for DV and ML patterning, and might be a downstream gene of BMP signaling.
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Proteínas Morfogenéticas Ósseas/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Morfogênese , Planárias/fisiologia , Regeneração , Proteínas com Domínio T/metabolismo , Animais , Padronização Corporal , Proteínas Morfogenéticas Ósseas/genética , Planárias/citologia , Transdução de Sinais , Proteínas com Domínio T/genéticaRESUMO
Horizontal gene transfer (HGT) refers to the movement of genetic material between distinct species by means other than sexual reproduction. HGT has contributed tremendously to the genome plasticity and adaptive evolution of prokaryotes and certain unicellular eukaryotes. The evolution of green plants from chlorophyte algae to angiosperms and from water to land represents a process of adaptation to diverse environments, which has been facilitated by acquisition of genetic material from other organisms. In this article, we review the occurrence of HGT in major lineages of green plants, including chlorophyte and charophyte green algae, bryophytes, lycophytes, ferns, and seed plants. In addition, we discuss the significance of horizontally acquired genes in the adaptive innovations of green plants and their potential applications to crop breeding and improvement.
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Transferência Genética Horizontal , Viridiplantae , Eucariotos , Evolução Molecular , Transferência Genética Horizontal/genética , Filogenia , Melhoramento Vegetal , Plantas/genéticaRESUMO
Graphene Oxide (GO)-related hydrogels have been extensively studied in hard tissue repair, because GO can not only enhance the mechanical properties of polymers but also promote osteogenic differentiation of mesenchymal stem cells. However, simple GO-related hydrogels are not ideal for the repair of osteoporotic bone defects as the overactive osteoclasts in osteoporosis. Alendronate (Aln) is known to inhibit osteoclasts and may bind to GO through covalent connection. Therefore, delivering Aln in GO-related hydrogels may be effective to repair osteoporotic bone defects. Here, we developed a control-released system which is constructed by collagen (Col)-GO sponges loaded with Aln (Col-GO-Aln) for osteoporotic bone defect repair. In vitro, Col-GO-Aln sponges prolonged the release period of Aln, and the sponge containing 0.05% (w/v) GO released Aln faster than sponge with 0.2% GO. Furthermore, tartrate-resistant acid phosphatase (TRAP) and F-actin staining demonstrated that Col-GO-Aln sponges effectively inhibited osteoclastogenesis of monocyte-macrophages. In vivo, micro-CT scan showed that the volume of newborn bone in defect site by 0.05% GO sponge was nearly three times larger than that of other groups. Moreover, the CT and histological examinations of rat femur proved that Col-GO-Aln sponges decreased the number of osteoclasts and suppressed the systemic bone loss in osteoporotic rats. These findings reveal that the application of GO as carriers of anti-osteoporosis drugs is a viable treatment for osteoporosis. The results also underscore the potential of GO-related hydrogels with Aln-releasing capacity for bone regeneration in osteoporosis.
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BACKGROUND: Cold, an environmental factor, induces many reproductive diseases. It is known that endothelin (ET) is a potent vasoconstrictor, and cold stress can increase the expression of ET and its receptors. The cold stress rat model was developed to examine two parameters: (1) the effects of cold stress on ovarian and uterine morphology, function, and microvascular circulation and (2) possible mechanisms of ET and its receptors involved in cold stress-induced menstruation disorders. METHODS: The rat cold stress model was prepared with an ice water bath. The estrous cycle was observed by methylene blue and hematoxylin and eosin (H&E) staining. Serum estradiol 2 (E2), testosterone (T), progesterone (P) were detected by radioimmunoassay. Hemorheology indices were measured. The real-time blood flow of auricle and uterine surfaces was measured. Expressions of CD34 and α-SMA in ovarian and uterine tissues were detected by immunohistochemistry. ET-1 contents in serum were tested, and expressions of ET-receptor types A and B (ET-AR and ET-BR) in ovarian tissues were detected via Western blotting. RESULTS: Cold stress extended the estrous cycle, thereby causing reproductive hormone disorder, imbalance of local endothelin/nitric oxide expression, and microcirculation disturbance. Cold-stress led to up-regulation of ET-AR expression and protein and down-regulation of ET-BR expression in rats. CONCLUSIONS: This study suggests that the reason for cold stress-induced dysfunction in reproductive organs may be closely related to the imbalance of ET-1 and its receptor expressions, leading to microvascular circulation disorders in local tissues.
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Resposta ao Choque Frio/fisiologia , Endotelinas/metabolismo , Microcirculação/fisiologia , Ovário/irrigação sanguínea , Útero/irrigação sanguínea , Actinas/metabolismo , Animais , Antígenos CD34/metabolismo , Endotelinas/sangue , Estradiol/sangue , Ciclo Estral/fisiologia , Feminino , Ovário/metabolismo , Progesterona/sangue , Ratos Sprague-Dawley , Receptores de Endotelina/metabolismo , Testosterona/sangue , Útero/metabolismoRESUMO
OBJECTIVE: To investigate the relationship between symptom patterns of cold coagulation and blood stasis (CCBS) and microcirculation disturbance. In addition, we determined the efficacy of modified Wenjing decoction (WJD) for the treatment of CCBS. METHODS: CCBS was induced in rats with an ice-water bath treatment. The ovarian function, microvascular and circulatory status of reproductive organs, and function of local microvascular endothelial cells (VECs) and vascular smooth muscle cells (VSMCs) were evaluated. RESULTS: Ovarian dysfunction was observed in the rats with CCBS. It was characterized by the presence of an estrous cycle disorder and a decrease in reproductive hormone levels. Microvascular circulation disorders were associated with an imbalance in vasoconstriction, relaxation substances, nitric oxide, abnormal blood flow in whole blood, and decreased blood flow in the auricle and uterus. VECs were damaged, and VSMCs contracted and proliferated in ovarian and uterine tissues. CONCLUSION: Our findings suggest that the dysfunctional reproductive organs observed in gynecological CCBS may be closely related to the microcirculation disturbance of local tissues, microvascular contraction, and vascular remodeling. Modified WJD can be used to treat CCBS by improving microcirculation in reproductive organs.
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Medicamentos de Ervas Chinesas/administração & dosagem , Microcirculação/efeitos dos fármacos , Doenças Vasculares Periféricas/tratamento farmacológico , Reprodução/efeitos dos fármacos , Animais , Temperatura Baixa , Resposta ao Choque Frio/efeitos dos fármacos , Feminino , Humanos , Ovário/efeitos dos fármacos , Ovário/fisiopatologia , Doenças Vasculares Periféricas/fisiopatologia , Ratos , Ratos Sprague-Dawley , Útero/efeitos dos fármacos , Útero/fisiopatologia , Vasoconstrição/efeitos dos fármacosRESUMO
The survival of transplanted cells and tissues in bone regeneration requires a microenvironment with a vibrant vascular network. A tissue engineering chamber can provide this in vivo. However, the commonly used silicone chamber is biologically inert and can cause rejection reactions and fibrous capsule. Studies have revealed that collagen is highly biocompatible and graphene oxide (GO) could regulate osteogenic activity in vivo. Besides, GO can be cross-linked with natural biodegradable polymers to construct scaffolds. Methods: A vascularized GO-collagen chamber model was built by placing vessels traversing through the embedded tissue-engineered grafts (osteogenic-induced bone mesenchymal stem cells -gelatin) in the rat groin area. Osteogenic activity and inflammatory reactions were assessed using different methods including micro-CT scanning, Alizarin red staining, and immunohistochemical staining. Results: After one month, in vivo results showed that bone mineralization and inflammatory responses were significantly pronounced in the silicone model or no chamber (control) groups. Vascular perfusion analysis confirmed that the GO-collagen chamber improved the angiogenic processes. Cells labeled with EdU revealed that the GO-collagen chamber promoted the survival and osteogenic differentiation of bone mesenchymal stem cells. Conclusion: Overall, the novel biocompatible GO-collagen chamber exhibited osteoinductive and anti-fibrosis effects which improved bone regeneration in vivo. It can, therefore, be applied to other fields of regenerative medicine.
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Materiais Biocompatíveis , Regeneração Óssea/efeitos dos fármacos , Colágeno , Grafite , Engenharia Tecidual , Alicerces Teciduais , Animais , Anti-Inflamatórios/uso terapêutico , Materiais Biocompatíveis/uso terapêutico , Calcificação Fisiológica/efeitos dos fármacos , Células Cultivadas , Colágeno/uso terapêutico , Feminino , Grafite/uso terapêutico , Células-Tronco Mesenquimais , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND: Impaired wound healing might be associated with many issues, especially overactive of reactive oxygen species (ROS), deficiency of blood vessels and immature of epidermis. N-acetylcysteine (NAC), as an antioxidant, could solve these problems by inhibiting overreactive of ROS, promoting revascularization and accelerating re-epithelialization. How to deliver NAC in situ with a controllable releasing speed still remain a challenge. MATERIALS AND METHODS: In this study, we combined collagen (Col) with N-acetylcysteine to perform the characteristics of sustained release and chemically crosslinked Col/NAC composite with polyamide (PA) nanofibers to enhance the mechanical property of collagen and fabricated this multi-layered scaffold (PA-Col/NAC scaffold). The physical properties of the scaffolds such as surface characteristics, water absorption and tensile modulus were tested. Meanwhile, the ability to promote wound healing in vitro and in vivo were investigated. RESULTS: These scaffolds were porous and performed great water absorption. The PA-Col/NAC scaffold could sustainably release NAC for at least 14 days. After cell implantation, PA-Col/NAC scaffold showed better cell proliferation and cell migration than the other groups. In vivo, PA-Col/NAC scaffolds could promote wound healing best among all the groups. CONCLUSION: The multi-layered scaffolds could obviously accelerate the process of wound healing and exert better and prolonged effects.
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Acetilcisteína/farmacologia , Colágeno/química , Sequestradores de Radicais Livres/farmacologia , Nylons/química , Reepitelização/efeitos dos fármacos , Alicerces Teciduais/química , Cicatrização/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Preparações de Ação Retardada , Masculino , Nanofibras/química , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismoRESUMO
Seed filling is a dynamic process that determines seed size and nutritional quality. This time-dependent trait follows a logistic (S-shaped) growth curve that can be described by a logistic function, with parameters of biological relevance. When compared between genotypes, the filling dynamics variations are explained by the differences of parameter values; as such, the parameter estimates can be considered as "traits" for genetic analysis to identify loci that are associated with the seed-filling process. We carried out genetic and genomic analysis of the seed-filling process in maize, using a recombinant inbred line (RIL) population derived from the two inbred lines with contrasting seed-filling dynamics. We recorded seed dry weight at 14 time points after pollination, spanning the early filling phases to the late maturation stages. Fitting these data to a logistic model allowed for estimating 12 characteristic parameters that can be used to meaningfully describe the seed-filling process. Quantitative trait locus (QTL) mapping of these parameters identified a total of 90 nonredundant loci. Using bulked segregant RNA-sequencing (BSR-seq) analysis, we identified eight genes that showed differential gene expression patterns at multiple time points between the extreme pools, and these genes co-localize with the mapped QTL regions. Two of the eight genes, GRMZM2G391936 and GRMZM2G008263, are implicated in starch and sucrose metabolism, and biosynthesis of secondary metabolites that are well known for playing a vital role in seed filling. This study suggests that the logistic model-based approach can efficiently identify genetic loci that regulate dynamic developing traits.