Meta-analysis reveals the effects of microbial inoculants on the biomass and diversity of soil microbial communities.

Microbial inoculation involves transplanting microorganisms from their natural habitat to new plants or soils to improve plant performance, and it is being increasingly used in agriculture and ecological restoration. However, microbial inoculants can invade and alter the composition of native microbial communities; thus, a comprehensive analysis is urgently needed to understand the overall impact of microbial inoculants on the biomass, diversity, structure and network complexity of native communities. Here we provide a meta-analysis of 335 studies revealing a positive effect of microbial inoculants on soil microbial biomass. This positive effect was weakened by environmental stress and enhanced by the use of fertilizers and native inoculants. Although microbial inoculants did not alter microbial diversity, they induced major changes in the structure and bacterial composition of soil microbial communities, reducing the complexity of bacterial networks and increasing network stability. Finally, higher initial levels of soil nutrients amplified the positive impact of microbial inoculants on fungal biomass, actinobacterial biomass, microbial biomass carbon and microbial biomass nitrogen. Together, our results highlight the positive effects of microbial inoculants on soil microbial biomass, emphasizing the benefits of native inoculants and the important regulatory roles of soil nutrient levels and environmental stress.

Development of a highly sensitive ampicillin sensor utilizing functionalized aptamers.

To develop a sensitive and simple ampicillin (AMP) sensor for trace antibiotic residue detection, the influencing factors of the modification effect of nanogold-functionalized nucleic acid sequences (Adenine: A, Thymine: T) were comprehensively analyzed in this study, including the modification method, base length and type. It was found that under the same base concentration, longer chains are more likely to reach saturation than shorter chains; and when the base concentration and length are both the same, A exhibits a higher saturation modification level compared to T. Based on these research findings, a highly sensitive fluorescence aptamer sensor for detecting ampicillin was constructed using the optimized functionalized sequence (ployA6-aptamer) and experimental conditions (6 hours binding time between nucleic acid aptamer and complementary strand, pH 7 working solution, 20 minutes detection time) based on the principle of fluorescence resonance energy transfer. The sensor has a detection range of 0.18 ng ml-1 to 3.11 ng ml-1 for ampicillin, with a detection limit of 0.04 ng ml-1. It exhibits significant selectivity and achieves an average recovery rate of 98.71% in tap water and 91.83% in milk. This method can be used not only for residual ampicillin detection, but also for highly sensitive detection of various antibiotics and small biological molecules by replacing the aptamer type. It provides a research basis for the design of highly sensitive fluorescence aptamer sensors and further applications of nanogold@DNA composite structures.

Spatiotemporal evolution and Sustainably comprehensive zoning optimization of production-living-ecological functions in the Mountain-Flatland areas.

Examining the spatiotemporal changes of territorial space is crucial for addressing the conflict between economic-social development and the natural environment and achieving optimal territorial space utilization. However, there is a research gap regarding the spatial characteristics and optimization in the mountain-flatland area. To address this gap, this paper focuses on the urban agglomeration in Central Yunnan (UACY) as a representative mountain-flatland area. A mountain-flatland classification model was established. Based on the evaluation of production- living- ecological functions, the economic models were introduced to measure the balance degree, and further researched the spatiotemporal evolution and coupling coordination characteristics by spatial analysis from 2010 to 2020. The findings indicate the following: (1) The study area exhibited distinct mountain-flatland differentiation, with "western mountainous counties (MCs)/semi-mountainous and semi-flatland counties (SMSFCs), central flatland counties (FCs), and eastern SMSFCs". production function (PF) primarily formed a cluster in the central-northeastern areas of FCs and of SMSFCs, living function (LF) was highly clustered in the central areas of FCs, remained stable, and ecological function (EF) was significantly clustered in the northwestern regions of MCs and of SMSFCs, significantly enhanced in the northeast. (2) The imbalance degree followed the order LF > PF > EF, showing a decreasing trend primarily driven by intra-group imbalances within FCs, SMSFCs, and MCs. The coordinate areas were mainly concentrated in central FCs, and the dysfunctional areas was largely located in MCs and SMSFCs, the degree was improved, especially in northwestern and southeastern MCs and SMSFCs. (3) The study area fell into 18 functional areas, optimized into 13 areas, with recommendations for differentiated development control paths to achieve an optimization of PLEFs. These results provide theoretical references for promoting sustainable utilization of territorial resources and facilitating high-quality regional development in UACY and other parts of the country.

Mineral-solubilizing microbial inoculant positively affects the multifunctionality of anthropogenic soils in abandoned mining areas.

The mining industry has a significant negative impact on ecosystems, and the remediation of abandoned mining sites requires effective strategies. One promising approach is the incorporation of mineral-solubilizing microorganisms into current external soil spray seeding technologies. These microorganisms possess the ability to decrease mineral particle sizes, promote plant growth, and enhance the release of vital soil nutrients. However, most previous studies on mineral-solubilizing microorganisms have been conducted in controlled greenhouse environments, and their practical application in field settings remains uncertain. To address this knowledge gap, we conducted a four-year field experiment at an abandoned mining site to investigate the efficacy of mineral-solubilizing microbial inoculants in restoring derelict mine ecosystems. We assessed soil nutrients, enzyme activities, functional genes, and soil multifunctionality. We also examined microbial compositions, co-occurrence networks, and community assembly processes. Our results demonstrated that the application of mineral-solubilizing microbial inoculants significantly enhanced soil multifunctionality. Interestingly, certain bacterial phyla or class taxa with low relative abundances were found to be key drivers of multifunctionality. Surprisingly, we observed no significant correlation between microbial alpha diversity and soil multifunctionality, but we did identify positive associations between the relative abundance and biodiversity of keystone ecological clusters (Module #1 and #2) and soil multifunctionality. Co-occurrence network analysis revealed that microbial inoculants reduced network complexity while increasing stability. Additionally, we found that stochastic processes played a predominant role in shaping bacterial and fungal communities, and the inoculants increased the stochastic ratio of microbial communities, particularly bacteria. Moreover, microbial inoculants significantly decreased the relative importance of dispersal limitations and increased the relative importance of drift. High relative abundances of certain bacterial and fungal phyla were identified as major drivers of the microbial community assembly process. In conclusion, our findings highlight the crucial role of mineral-solubilizing microorganisms in soil restoration at abandoned mining sites, shedding light on their significance in future research endeavors focused on optimizing the effectiveness of external soil spray seeding techniques.

Lin28a maintains a subset of adult muscle stem cells in an embryonic-like state.

During homeostasis and after injury, adult muscle stem cells (MuSCs) activate to mediate muscle regeneration. However, much remains unclear regarding the heterogeneous capacity of MuSCs for self-renewal and regeneration. Here, we show that Lin28a is expressed in embryonic limb bud muscle progenitors, and that a rare reserve subset of Lin28a+Pax7- skeletal MuSCs can respond to injury at adult stage by replenishing the Pax7+ MuSC pool to drive muscle regeneration. Compared with adult Pax7+ MuSCs, Lin28a+ MuSCs displayed enhanced myogenic potency in vitro and in vivo upon transplantation. The epigenome of adult Lin28a+ MuSCs showed resemblance to embryonic muscle progenitors. In addition, RNA-sequencing revealed that Lin28a+ MuSCs co-expressed higher levels of certain embryonic limb bud transcription factors, telomerase components and the p53 inhibitor Mdm4, and lower levels of myogenic differentiation markers compared to adult Pax7+ MuSCs, resulting in enhanced self-renewal and stress-response signatures. Functionally, conditional ablation and induction of Lin28a+ MuSCs in adult mice revealed that these cells are necessary and sufficient for efficient muscle regeneration. Together, our findings connect the embryonic factor Lin28a to adult stem cell self-renewal and juvenile regeneration.

Adult progenitor rejuvenation with embryonic factors.

During ageing, adult stem cells' regenerative properties decline, as they undergo replicative senescence and lose both their proliferative and differentiation capacities. In contrast, embryonic and foetal progenitors typically possess heightened proliferative capacities and manifest a more robust regenerative response upon injury and transplantation, despite undergoing many rounds of mitosis. How embryonic and foetal progenitors delay senescence and maintain their proliferative and differentiation capacities after numerous rounds of mitosis, remains unknown. It is also unclear if defined embryonic factors can rejuvenate adult progenitors to confer extended proliferative and differentiation capacities, without reprogramming their lineage-specific fates or inducing oncogenic transformation. Here, we report that a minimal combination of LIN28A, TERT, and sh-p53 (LTS), all of which are tightly regulated and play important roles during embryonic development, can delay senescence in adult muscle progenitors. LTS muscle progenitors showed an extended proliferative capacity, maintained a normal karyotype, underwent myogenesis normally, and did not manifest tumorigenesis nor aberrations in lineage differentiation, even in late passages. LTS treatment promoted self-renewal and rescued the pro-senescence phenotype of aged cachexia patients' muscle progenitors, and promoted their engraftment for skeletal muscle regeneration in vivo. When we examined the mechanistic basis for LIN28A's role in the LTS minimum combo, let-7 microRNA suppression could not fully explain how LIN28A promoted muscle progenitor self-renewal. Instead, LIN28A was promoting the translation of oxidative phosphorylation mRNAs in adult muscle progenitors to optimize mitochondrial reactive oxygen species (mtROS) and mitohormetic signalling. Optimized mtROS induced a variety of mitohormetic stress responses, including the hypoxic response for metabolic damage, the unfolded protein response for protein damage, and the p53 response for DNA damage. Perturbation of mtROS levels specifically abrogated the LIN28A-driven hypoxic response in Hypoxia Inducible Factor-1α (HIF1α) and glycolysis, and thus LTS progenitor self-renewal, without affecting normal or TS progenitors. Our findings connect embryonically regulated factors to mitohormesis and progenitor rejuvenation, with implications for ageing-related muscle degeneration.

The positive effects of mineral-solubilizing microbial inoculants on asymbiotic nitrogen fixation of abandoned mine soils are driven by keystone phylotype.

Toward the restoration of the increasing numbers of abandoned mines across China, external-soil spray seeding technologies have become more extensively utilized. However, considerable challenges remain that seriously hamper the effectiveness of these technologies, such as inadequate nutrient availability for plants. Previous studies have shown that mineral-solubilizing microbial inoculants can increase the nodules of legumes. However, their effects on symbiotic nitrogen fixation (SNF), asymbiotic nitrogen fixation (ANF), and diazotrophic communities remain unknown. Further, research into the application of functional microorganisms for the restoration of abandoned mines has been conducted either in greenhouses, or their application in the field has been too brief. Thus, we established a four-year field experiment in an abandoned mine and quantified the SNF, ANF, and diazotrophic communities. To the best of our knowledge, this study is the first to describe the long-term application of specific functional microorganisms for the remediation of abandoned mine sites in the field. We revealed that mineral-solubilizing microbial inoculants significantly increased the soil ANF rate and SNF content. There was no significant correlation between the diazotrophic alpha diversity and soil ANF rate; however, there were strong positive associations between the relative abundance and biodiversity of keystone phylotype (module #5) within ecological clusters and the ANF rate. Molecular ecological networks indicated that microbial inoculants increased network complexity and stability. Moreover, the inoculants significantly enhanced the deterministic ratio of diazotrophic communities. Furthermore, homogeneous selection predominantly mediated the assembly of soil diazotrophic communities. It was concluded that mineral-solubilizing microorganisms played a critical role in maintaining and enhancing nitrogen, which offers a new solution with great potential for the restoration of ecosystems at abandoned mine sites.

Plant and Native Microorganisms Amplify the Positive Effects of Microbial Inoculant.

Microbial inoculants can be used to restore abandoned mines because of their positive effects on plant growth and soil nutrients. Currently, soils in greenhouse pot studies are routinely sterilized to eradicate microorganisms, allowing for better inoculant colonization. Large-scale field sterilization of abandoned mining site soils for restoration is difficult, though. In addition, microbial inoculants have an impact on plants. Plants also have an impact on local microbes. The interactions among microbial inoculants, native microorganisms, and plants, however, have not been studied. We created a pot experiment utilizing the soil and microbial inoculant from a previous experiment because it promoted plant growth in that experiment. To evaluate the effects of the plants, native microorganisms, and microbial inoculants, we assessed several indicators related to soil elemental cycling and integrated them into the soil multifunctionality index. The addition of the microbial inoculant and sterilizing treatment had a significant impact on alfalfa growth. When exposed to microbial inoculant treatments, the plant and sterilization treatments displayed radically different functional characteristics, where most of the unsterilized plant treatment indices were higher than those of the others. The addition of microbial inoculant significantly increased soil multifunctionality in plant treatments, particularly in the unsterilized plant treatment, where the increase in soil multifunctionality was 260%. The effect size result shows that the positive effect of microbial inoculant on soil multifunctionality and unsterilized plant treatment had the most significant promotion effect. Plant and native microorganisms amplify the positive effects of microbial inoculant.

Endocytosis-mediated triple-activable prodrug nanotherapeutics potentiating therapeutic efficacy and security towards solid tumors.

Self-assembling prodrug nanotherapeutics have emerged as a promising nanoplatform for anticancer drug delivery. The specific and efficient activation of prodrug nanotherapeutics inside tumor cells is vital for the antitumor efficacy and security. Herein, a triple-activable prodrug polymer (TAP) is synthesized by conjugating polyethylene glycol-poly-(caprolactone)-paclitaxel (PTX) polymer with two tumor-responsive bonds, disulfide and acetal. TAP could self-assemble into nanotherapeutics (TAP NTs) free of surfactant with a high drug loading (32.6%). In blood circulation, TAP NTs could remain intact to efficiently accumulate in tumor sites. Thereafter, tumor cells would internalize TAP NTs through multiple endocytosis pathways. Inside tumor cells, TAP NTs could be activated to release PTX and induce tumor cell apoptosis in triple pathways: (i) lysosomal acidity rapid activation; (ii) ROS-acidity tandem activation and (iii) GSH-acidity tandem activation. Compared with Taxol and non-activable control, TAP NTs significantly potentiate the antitumor efficacy and security of PTX against solid tumors including breast cancer and colon cancer.

Machine learning-based phenotypic screening for postmitotic growth inducers uncover vitamin D3 metabolites as small molecule ribosome agonists.

OBJECTIVES: To restore tissue growth without increasing the risk for cancer during aging, there is a need to identify small molecule drugs that can increase cell growth without increasing cell proliferation. While there have been numerous high-throughput drug screens for cell proliferation, there have been few screens for post-mitotic anabolic growth. MATERIALS AND METHODS: A machine learning (ML)-based phenotypic screening strategy was used to discover metabolites that boost muscle growth. Western blot, qRT-PCR and immunofluorescence staining were used to evaluate myotube hypertrophy/maturation or protein synthesis. Mass spectrometry (MS)-based thermal proteome profiling-temperature range (TPP-TR) technology was used to identify the protein targets that bind the metabolites. Ribo-MEGA size exclusion chromatography (SEC) analysis was used to verify whether the ribosome proteins bound to calcitriol. RESULTS: We discovered both the inactive cholecalciferol and the bioactive calcitriol are amongst the top hits that boost post-mitotic growth. A large number of ribosomal proteins' melting curves were affected by calcitriol treatment, suggesting that calcitriol binds to the ribosome complex directly. Purified ribosomes directly bound to pure calcitriol. Moreover, we found that calcitriol could increase myosin heavy chain (MHC) protein translation and overall nascent protein synthesis in a cycloheximide-sensitive manner, indicating that calcitriol can directly bind and enhance ribosomal activity to boost muscle growth. CONCLUSION: Through the combined strategy of ML-based phenotypic screening and MS-based omics, we have fortuitously discovered a new class of metabolite small molecules that can directly activate ribosomes to promote post-mitotic growth.

Pathogenesis of sarcopenia and the relationship with fat mass: descriptive review.

Age-associated obesity and muscle atrophy (sarcopenia) are intimately connected and are reciprocally regulated by adipose tissue and skeletal muscle dysfunction. During ageing, adipose inflammation leads to the redistribution of fat to the intra-abdominal area (visceral fat) and fatty infiltrations in skeletal muscles, resulting in decreased overall strength and functionality. Lipids and their derivatives accumulate both within and between muscle cells, inducing mitochondrial dysfunction, disturbing ß-oxidation of fatty acids, and enhancing reactive oxygen species (ROS) production, leading to lipotoxicity and insulin resistance, as well as enhanced secretion of some pro-inflammatory cytokines. In turn, these muscle-secreted cytokines may exacerbate adipose tissue atrophy, support chronic low-grade inflammation, and establish a vicious cycle of local hyperlipidaemia, insulin resistance, and inflammation that spreads systemically, thus promoting the development of sarcopenic obesity (SO). We call this the metabaging cycle. Patients with SO show an increased risk of systemic insulin resistance, systemic inflammation, associated chronic diseases, and the subsequent progression to full-blown sarcopenia and even cachexia. Meanwhile in many cardiometabolic diseases, the ostensibly protective effect of obesity in extremely elderly subjects, also known as the 'obesity paradox', could possibly be explained by our theory that many elderly subjects with normal body mass index might actually harbour SO to various degrees, before it progresses to full-blown severe sarcopenia. Our review outlines current knowledge concerning the possible chain of causation between sarcopenia and obesity, proposes a solution to the obesity paradox, and the role of fat mass in ageing.

Water Level Has Higher Influence on Soil Organic Carbon and Microbial Community in Poyang Lake Wetland Than Vegetation Type.

Although microorganisms play a key role in the carbon cycle of the Poyang Lake wetland, the relationship between soil microbial community structure and organic carbon characteristics is unknown. Herein, high-throughput sequencing technology was used to explore the effects of water level (low and high levels above the water table) and vegetation types (Persicaria hydropiper and Triarrhena lutarioriparia) on microbial community characteristics in the Poyang Lake wetland, and the relationships between soil microbial and organic carbon characteristics were revealed. The results showed that water level had a significant effect on organic carbon characteristics, and that soil total nitrogen, organic carbon, recombinant organic carbon, particle organic carbon, and microbial biomass carbon were higher at low levels above the water table. A positive correlation was noted between soil water content and organic carbon characteristics. Water level and vegetation type significantly affected soil bacterial and fungal diversity, with water level exerting a higher effect than vegetation type. The impacts of water level and vegetation type were higher on fungi than on bacteria. The bacterial diversity and evenness were significantly higher at high levels above the water table, whereas an opposite trend was noted among fungi. The bacterial and fungal richness in T. lutarioriparia community soil was higher than that in P. hydropiper community soil. Although both water level and vegetation type had significant effects on bacterial and fungal community structures, the water level had a higher impact than vegetation type. The bacterial and fungal community changes were the opposite at different water levels but remained the same in different vegetation soils. The organic carbon characteristics of wetland soil were negatively correlated with bacterial diversity but positively correlated with fungal diversity. Soil water content, soluble organic carbon, C/N, and microbial biomass carbon were the key soil factors affecting the wetland microbial community. Acidobacteria, Alphaproteobacteria, Verrucomicrobia, Gammaproteobacteria, and Eurotiomycetes were the key microbiota affecting the soil carbon cycle in the Poyang Lake wetland. Thus, water and carbon sources were the limiting factors for bacteria and fungi in wetlands with low soil water content (30%). Hence, the results provided a theoretical basis for understanding the microbial-driven mechanism of the wetland carbon cycle.

Construction and Characterization of an Aeromonas hydrophila Multi-Gene Deletion Strain and Evaluation of Its Potential as a Live-Attenuated Vaccine in Grass Carp.

Aeromonas hydrophila is an important pathogen that causes motile Aeromonas septicemia (MAS) in the aquaculture industry. Aerolysin, hemolysin, serine protease and enterotoxins are considered to be the major virulence factors of A. hydrophila. In this study, we constructed a five-gene (aerA, hly, ahp, alt and ast) deletion mutant strain (named Aeromonas hydrophila five-gene deletion strain, AHFGDS) to observe the biological characteristics and detect its potential as a live-attenuated vaccine candidate. AHFGDS displayed highly attenuated and showed increased susceptibility to fish blood and skin mucus killing, while the wild-type strain ZYAH72 was highly virulent. In zebrafish (Danio rerio), AHFGDS showed a 240-fold higher 50% lethal dose (LD50) than that of the wild-type strain. Immunization with AHFGDS by intracelomic injection or immersion routes both provided grass carp (Ctenopharyngodon idella) significant protection against the challenge of the strain ZYAH72 or J-1 and protected the fish organs from serious injury. Further agglutinating antibody titer test supported that AHFGDS could elicit a host-adaptive immune response. These results suggested the potential of AHFGDS to serve as a live-attenuated vaccine to control A. hydrophila infection in aquaculture.

Effects of mineral-solubilizing microbial strains on the mechanical responses of roots and root-reinforced soil in external-soil spray seeding substrate.

There are a large number of abandoned mining areas in China, where external-soil spray seeding is a common technique used to assist with the restoration of these areas. However, the soil component of external-soil spray seeding is deficient, and they are prone to collapse, which complicates ecological restoration. In this study, we added a mineral-solubilizing microbial strain to an external-soil spray seeding substrate in Robinia pseudoacacia and Lespedeza bicolor pots, which were monitored from December 2018 to November 2019. We investigated their root growth and root tensile properties, as well as root-reinforced soil shear strength. The results revealed that the addition of the microbial strain in the substrate improved root growth of Robinia pseudoacacia. The root-reinforced soil shear strength, tensile force and strength were also strengthened by the added microbial strain. Although the growth rate of Robinia pseudoacacia was faster than that of Lespedeza bicolor, the shear strength of the root-reinforced Robinia pseudoacacia soil was lower than that of the Lespedeza bicolor root-reinforced soil of the same diameter. Finally, compared with the cohesion, the change in the friction angle is relatively small, and differences in cohesion resulted in shear strength changes under the same treatment. Our results suggested that the addition of a mineral-solubilizing microbial strain to the external-soil spray seeding substrate could help plants strengthen the soil and positively enhance its effects. These results might also enrich the existing data on the effects of mineral-solubilizing microbial strains on plant roots, while guiding further studies toward improving the efficacy of external-soil spray seeding technologies.

Injectable chitosan thermogels for sustained and localized delivery of pingyangmycin in vascular malformations.

Pingyangmycin (PYM) is an effective drug to treat vascular malformations (VM), but can easily diffuse from the injection site, which will reduce its therapeutic effect and increase side effect. Our study was to evaluate PYM-loaded chitosan thermogels for sustained and localized embolization therapy. It was shown that in vitro release of PYM thermogels could be delayed up to 12 days. The results measured by MTT assay showed that PYM thermogels could inhibit proliferation and induce apoptosis of EA.hy926 cells in a concentration and time dependent manner. In vivo pharmacokinetics study demonstrated that compared with PYM injections, PYM thermogels had a better sustained delivery of PYM. Macroscopic observation and histological examination of rabbit ear veins displayed that after administration with PYM thermogels for 18 days, obvious venous embolization and inflammatory response could be found. These results indicate that PYM thermogels is likely to achieve excellent prospects for VM treatment.

Intravenous microemulsion of docetaxel containing an anti-tumor synergistic ingredient (Brucea javanica oil): formulation and pharmacokinetics.

The purpose of this study was to develop a docetaxel microemulsion containing an anti-tumor synergistic ingredient (Brucea javanica oil) and to investigate the characteristics of the microemulsion. Brucea javanica oil contains oleic acid and linoleic acids that have been shown by animal and human studies to inhibit tumor formation. The microemulsion containing Brucea javanica oil, medium-chain triglyceride, soybean lecithin, Solutol®HS 15, PEG 400, and water was developed for docetaxel intravenous administration. A formulation with higher drug content, lower viscosity, and smaller particle size was developed. The droplet size distribution of the dispersed phase of the optimized microemulsion was 13.5 nm, determined using a dynamic light scattering technique. The small droplet size enabled the microemulsion droplets to escape from uptake and phagocytosis by the reticuloendothelial system and increased the circulation time of the drug. The zeta potential was -41.3 mV. The optimized microemulsion was pale yellow, transparent, and non-opalescent in appearance. The value of the combination index was 0.58, showing that there was a synergistic effect when docetaxel was combined with Brucea javanica oil. After a single intravenous infusion dose (10 mg/kg) in male Sprague Dawley rats, the area under the curve of the microemulsion was higher and the half-time was longer compared with that of docetaxel solution alone, and showed superior pharmacokinetic characteristics. These results indicate that this preparation of docetaxel in emulsion is likely to provide an excellent prospect for clinical tumor treatment.

A novel bi-layer ascending release osmotic pump tablet: in vitro investigation and in vivo investigation in pharmacokinetic study and IVIVC evaluation.

This study was aimed to develop an ascending release push-pull osmotic pump (APOP) system with a novel mechanism and an easy manufacture process. Theoretical analysis showed that the key to obtain the non-zero order drug release was to break the balance between the drug suspension release rate in the drug layer and the swelling rate of the core, and an ascending drug release rate was achieved when the former was slower than the latter. A polymer (Polyox WSR N-12K) was introduced as a suspension agent in drug layer to slow down the hydration rate of drug layer. Influence of the composition of drug layer (PEO category, total amount, drug loading and fraction of NaCl), push layer (NaCl amount), and also the level of coating weight gain on the drug release profiles was investigated. Observation of hydration state was estimated by taking photos, and also was confirmed by the theories. Paliperidone was delivered successfully by APOP at an ascending release rate up to 20 h in vitro. The in vivo plasma concentration of paliperidone in beagle dogs increased gradually up to 19 h. The APOP with an easy manufacture process was a promising strategy to deliver drug at an ascending rate.

Fabrication of carvedilol nanosuspensions through the anti-solvent precipitation-ultrasonication method for the improvement of dissolution rate and oral bioavailability.

The present study aims to prepare carvedilol (CAR) nanosuspensions using the anti-solvent precipitation-ultrasonication technique to improve its dissolution rate and oral bioavailability. Alpha-tocopherol succinate (VES) was first used as a co-stabilizer to enhance the stability of the nanosuspensions. The effects of the process parameters on particle size of the nanosuspensions were investigated. The optimal values of the precipitation temperature, power inputs, and the time length of ultrasonication were selected as 10°C, 400 W, and 15 min, respectively. Response surface methodology based on central composite design was utilized to evaluate the formulation factors that affect the size of nanosuspensions, i.e., the concentration of CAR and VES in the organic solution, and the level of sodium dodecyl sulfate in the anti-solvent phase, respectively. The optimized formulation showed a mean size of 212 ± 12 nm and a zeta potential of -42 ± 3 mV. Scanning electron microscopy revealed that the nanosuspensions were flaky-shaped. Powder X-ray diffraction and differential scanning calorimetry analysis confirmed that the nanoparticles were in the amorphous state. Fourier transform infrared analysis demonstrated that the reaction between CAR and VES is probably due to hydrogen bonding. The nanosuspension was physically stable at 25°C for 1 week, which allows it to be further processing such as drying. The dissolution rate of the nanosuspensions was markedly enhanced by reducing the size. The in vivo test demonstrated that the C(max) and AUC(0-36) values of nanosuspensions were approximately 3.3- and 2.9-fold greater than that of the commercial tablets, respectively.

Novel surface-modified nanostructured lipid carriers with partially deacetylated water-soluble chitosan for efficient ocular delivery.

The objective of this study was to propose novel surface-modified nanostructured lipid carriers with partially deacetylated water-soluble chitosan (NLC-PDSC) as an efficient ocular delivery system to improve its transcorneal penetration and precorneal retention. PDSC with a deacetylation degree of around 50% was synthesized using an improved method. NLC loaded with flurbiprofen (FB) were prepared by melt emulsification method. They presented spherical morphology under both transmission electron microscope and scanning electron microscope. After coating with 0.15% (w/v) PDSC solution, the NLC showed a core-shell structure and a reversed zeta potential. The enhanced transcorneal penetration of the coated NLC was evaluated using isolated rabbit corneas, with significantly increased apparent permeability coefficient being 1.40- and 1.75-fold of the NLC and FB phosphate solution (FB-sol; p < 0.05), respectively. Precorneal retention assessed by gamma scintigraphy in vivo showed that the area under the remaining activity-time curve of the PDSC-coated formulation was 1.3-fold of the NLC and 2.4-fold of FB-sol. Moreover, in vivo ocular tolerance study indicated that there was no difference in irritation between the coated and noncoated NLC. In conclusion, novel NLC demonstrate high potential for ocular drug delivery.