Slower Degradation Rate Research Articles

Injectable and high-strength PLGA/CPC loaded ALN/MgO bone cement for bone regeneration by facilitating osteogenesis and inhibiting osteoclastogenesis in osteoporotic bone defects

Osteoporosis (OP) can result in slower bone regeneration than the normal condition due to the imbalance between osteogenesis and osteoclastogenesis, making osteoporotic bone defects healing a significant clinical challenge. Calcium phosphate cement (CPC) is a promising bone substitute material due to its good osteoinductive activity, however, the drawbacks such as fragility, slow degradation rate and incapability to control bone loss restrict its application in osteoporotic bone defects treatment. Currently, we developed the PLGA electrospun nanofiber sheets to carry alendronate (ALN) and magnesium oxide nanoparticle (nMgO) into CPC, therefore, to obtain a high-strength bone cement (C/AM-PL/C). The C/AM-PL/C bone cement had high mechanical strength, anti-washout ability, good injection performance and drug sustained release capacity. More importantly, the C/AM-PL/C cement promoted the osteogenic differentiation of bone marrow mesenchymal stem cells and neovascularization via the release of Mg2+ (from nMgO) and Ca2+ (during the degradation of CPC), and inhibited osteoclastogenesis via the release of ALN in vitro. Moreover, the injection of C/AM-PL/C cement significantly improved bone healing in an OP model with femur condyle defects in vivo. Altogether, the injectable C/AM-PL/C cement could facilitate osteoporotic bone regeneration, demonstrating its capacity as a promising candidate for treatment of osteoporotic bone defects.

Utilizing PET bottles for sustainable cellular reinforcement: A study on enhancing fly ash backfill bearing strength with innovative geocell alternative

The slow degradation rate is one of the major global concerns. Only, 60 % produced is being recycled. Among these waste materials, Polyethylene Terephthalate (PET) bottles contribute around 10 % to the total plastic waste produced. The recycling process of PET bottles considering existing capacity in environmentally responsible ways is limited. It is estimated that 60 % of PET bottles produced are being disposed of in landfills. To overcome this, past studies have suggested novel approaches for using it as substitute for conventional geocell as soil reinforcement and stability. However, past studies mostly focused on application of PET bottles as flaked, shreds and sliced form. The present study attempts on application of PET bottles under fly ash (FA) backfills without mechanical alterations. Full-scale experiments were conducted on FA backfill system, for both unreinforced and reinforced conditions. A comparative study was performed between high-density polyethylene (HDPE) geocell and PET bottle mattress to assess the bearing strength of the FA backfill. Experiments were performed in a 1 m3 tank with a loading plate width of 200 mm. Vertical loading was applied onto the backfill footing (for all the trial series), till the footing settlement of 40 mm is achieved. An aspect ratio of 2 was considered for HDPE geocell and PET bottles. Rock quarry dust (RQD) was considered as cell infill and overlay material on FA backfill. The test results showed that settlement accumulation rate was low under reinforced scenario compared to the unreinforced condition, with higher resilient (elastic) settlement. RQD over the PET-reinforced zone was also seen to have enhanced the load distribution aspect, thereby reducing deformation in PET reinforcement. This usage of waste material will contribute towards sustainable development. This work demonstrates the feasibility and effectiveness of PET reinforcement to be used as replacement for HDPE geocell, which eventually can agument the design methodology of structural backfills.

Cerium-oxide functionalized iron scaffolds: A synergistic approach for enhanced degradation and reduced cytotoxicity

Biodegradable scaffolds play a crucial role in biomedical restoration. These are three-dimensional (3D) structures that can provide support for the development of newly formed bone tissues. Among the studied metallic biodegradable scaffolds, those composed of iron (Fe) are notable for their high mechanical resistance. However, the slow degradation rate of Fe and the potential cytotoxicity of its degradation products pose challenges to effective osseointegration. Cerium oxide was incorporated into Fe scaffolds to overcome these two inherent limitations.We employed the dynamic hydrogen bubbling template (DHBT) technique, utilizing a citric acid-based electrolyte, to produce iron scaffolds. This same technique was used to embed cerium oxide nanoparticles (CNFe), whereas electrodeposition was used to create a thin cerium oxide coating over the scaffolds (CCFe). The oxidation state of cerium oxide in the functionalized scaffolds was scrutinized through surface characterization techniques. Ensuring similar porosities, we evaluated the degradation of the different distinct scaffolds using electrochemical techniques.The impact of cerium incorporation within or over the scaffolds on their degradation and cell viability was correlated with cerium oxidation states and the nature of the resulting degradation products. The synergistic implications of adding cerium to the iron scaffolds were thoroughly explored, and their potential benefits in future clinical settings were discussed.

Degradation behavior and osteogenic activity of octacalcium phosphate modified MgO coatings on magnesium

To further enhance the corrosion resistance and osteogenic activity of the porous micro-arc oxidation (MAO) derived MgO ceramic coating on biomedical magnesium (Mg), octacalcium phosphate (OCP) layers with different microstucture were prepared on MAO coating by chemical deposition (CD) method to fabricate MAO/CD composite coatings. The in vitro degradation behaviors of MAO/CD-coated samples were evaluated by immersion in simulated body fluid (SBF) and electrochemical impedance spectroscopy (EIS) measurement. Their effects on in vitro MC3T3-E1 cell differentiation were investigated by examining alkaline phosphatase (ALP) activity and expression of main osteogenic-related genes. The in vitro immersion tests show that MAO/CD coatings rarely experience destruction and only micro-cracks occur after 96 h. EIS tests indicate that MAO/CD coatings slow down the degradation rate of Mg observably. In addition, MAO/CD coatings improve osteogenic differentiation of MC3T3-E1 cells compared to MAO coating, which is ascribed the lightened alkalization of the surrounding medium as well as up-regulated intracellular Ca2+. MAO/CD coating deposited in 2 h endows Mg the slowest degradation rate and excellent osteogenic differentiation induction activity.

3D cell culture of nanofiber hydrogel promotes the growth and osteogenesis of bone marrow mesenchymal stem cells (BMSC)

Hydrogels, as a type of polymer network material with high water content, find wide application in various tissue repair procedures. In addition, a three-dimension (3D) cell culture platform similar to natural extracellular matrix can be constructed in vitro by modifying natural polymer chains. Therefore, this study based on natural polymer hydrogel, the introduction of inorganic nanoparticles POSS to prepare GelMA-POSS nanohydrogel. The physical and chemical properties of the hydrogel were evaluated through SEM, swelling test and degradation analysis. Subsequently, the GelMA-POSS nano-hydrogel was used as matrix material to culture rBMSCs in vitro. CCK-8 and flow cytometry were used to detect the proliferation ability and apoptosis rate of rBMSCs. The expression of osteogenic markers in rBMSCs was detected by qPCR, Western Blotting and ELISA assay, and the osteogenic differentiation of rBMSCs was detected by ALP staining and alizarin red staining. The results indicate that compared with pure gelatin (Gel) hydrogel, GelMA-POSS nanohydrogel has slower degradation rate and better water retention capacity. Furthermore, in vitro cell culture experiments showed that GelMA-POSS nano-hydrogel had good biocompatibility, and could promote the proliferation of rBMSCs and increase the expression level of osteogenic markers in cells, and induce osteogenic differentiation of rBMSCs. GelMA-POSS nano-hydrogel based on POSS significantly improves the physical and chemical properties of Gel hydrogel, and has good biocompatibility and the ability to induce osteogenic differentiation of rBMSCs, Thus, it holds great promise as a potential material for repairing bone defects.

Identification of Bacterial Species Capable of Degrading LDPE

Abstract: The Plastic is polymeric material having capability of being molded or shaped by the application of heat and pressure. The low-density polyethylene(LDPE) is the type of plastic which is used in various purpose of our daily life. It is one of the major environmental problems because of its slow degradation rate .To control the pollution caused by low-density polyethylene, microbes are isolated from the dumping site of the Durg region of Chhattisgarh. These microbes are screened by the zone of clearance method for degradation of low-density polyethylene using PEG as substrate. The screened microbes were identified by morphological and biochemical characteristics.Nine bacterial isolates was selected for biodegradation studies.Confirmation of bacterial biodegradation of low-density polyethylene was performed by using weight loss measurement and pH change due to production of acidic product.One potential isolate were further identified through 16S rRNA sequences Alcaligenes faecalis was shown the high degradation rate of low-density polyethylene

Mechanical properties of hydrated electrospun polycaprolactone (PCL) nanofibers

Polycaprolactone (PCL) nanofibers are a promising material for biomedical applications due to their biocompatibility, slow degradation rate, and thermal stability. We electrospun PCL fibers onto a striated substrate with 12 μm wide ridges and grooves and determined their mechanical properties in an aqueous solution with a combined atomic force/inverted optical microscopy technique. Fiber diameters, D, ranged from 27 to 280 nm. The hydrated PCL fibers had an extensibility (breaking strain), εmax, of 137%. The Young's modulus, E, and tensile strength, σT, showed a strong dependence on fiber diameter, D; decreasing steeply with increasing diameter, following empirical equations E(D)=(4.3∙103∙e−D51nm+1.1∙102) MPa and σT(D)=(2.6∙103∙e−D55nm+0.6∙102) MPa. Incremental stress-strain measurements were employed to investigate the viscoelastic behavior of these fibers. The fibers exhibited stress relaxation with a fast and slow relaxation time of 3.7 ± 1.2 s and 23 ± 8 s and these experiments also allowed the determination of the elastic and viscous moduli. Cyclic stress-strain curves were used to determine that the elastic limit of the fibers, εelastic, is between 19% and 36%. These curves were also used to determine that these fibers showed small energy losses (<20%) at small strains (ε < 10%), and over 50% energy loss at large strains (ε > 50%), asymptotically approaching 61%, as Eloss=61%·(1−e−0.04*ε). Our work is the first mechanical characterization of hydrated electrospun PCL nanofibers; all previous experiments were performed on dry PCL fibers, to which we will compare our data.

CHITOSAN COLLAGEN HYDROGEL: A POTENTIAL SCAFFOLD BIOMATERIAL FOR PERIODONTAL REGENERATIVE TREATMENT

Introduction: Hydrogels are considered a promising scaffold biomaterial for regenerative periodontal treatment. The development of collagen and chitosan based hydrogels can improve the final characteristics of the hydrogel. Review: Collagen and chitosan are the two main materials used to design scaffolds for tissue engineering. Collagen is a material that is often used to develop hydrogels because it has the advantage of high biocompatibility. In the biomedical field, collagen is often used as a drug delivery system. Collagen has weak mechanical strength so other biomaterials are needed for its use. Chitosan material has high biocompatibility and a slow degradation rate. So the combination of these two materials is a strategic choice for making promising biomaterial scaffolds in periodontal regenerative treatment. Conclusion: Chitosan collagen hydrogel is a potential scaffold biomaterial for periodontal regenerative treatment.

An In Situ-Gelling Conductive Hydrogel for Potential Use in Neural Tissue Engineering.

Cerebral cavitation is usual following acute brain injuries, such as stroke and traumatic brain injuries, as well as after tumor resection. Minimally invasive implantation of an injectable scaffold in the cavity is a promising approach for potential regeneration of tissue loss. This study aimed at designing an in situ-gelling conductive hydrogel containing silk fibroin (SF), brain decellularized extracellular matrix (dECM), and carbon nanotubes (CNT) for potential use in brain tissue regeneration. Two percent w/v SF hydrogels with different concentrations of dECM (0.1%, 0.2%, or 0.3% w/v) and CNTs (0.05%, 0.1%, or 0.25% w/v) were fabricated and characterized. It was observed that with the addition of dECM, the porosity decreased, whereas swelling and electrical conductivity tended to increase. The addition of dECM also led to a faster resorption rate, but no significant change in compressive modulus. Addition of CNTs, on the other hand, led to a denser, stronger, and more regular porous structure, higher swelling ratio, faster gelation time, slower degradation rate, and a significant increase in electrical conductivity. dECM and CNTs combined together resulted in superior porosity, swelling, resorption rate, mechanical properties, and electrical conductivity compared with SF scaffolds containing only dECM or CNTs. Hydrogel samples containing 2% SF, 0.3% dECM, and 0.1% CNTs had a high porosity (58.9%), low swelling ratio (15.9%), high conductivity (2.35 × 10-4 S/m), and moderate degradation rate (37.3% after 21 days), appropriate for neural tissue engineering applications. Cell evaluation studies also showed that the hydrogel systems support the cell adhesion and growth, with no sign of significant cytotoxicity. Impact statement Tissue loss and formation of a fluid-filled cavity following stroke, traumatic brain injury, or brain tumor resection lead to sensorimotor and/or cognitive deficits. The lack of a healthy extracellular matrix in the cavity avoids the endogenous cell migration and axonal sprouting and may also worsen the secondary injuries to peri-lesional tissue. Due to the brain anatomy, simple implantation of tissue engineering scaffolds to the injured site is not possible in many cases. Therefore, the development of injectable scaffolds that support neural growth and differentiation is crucial for tissue repair or limiting the expansion of damage region.

Homocysteine-potentiated Kelch-like ECH-associated protein 1 promotes senescence of neuroblastoma 2a cells via inhibiting ubiquitination of β-catenin.

Elevated serum homocysteine (Hcy) level is a risk factor for Alzheimer's disease (AD) and accelerates cell aging. However, the mechanism by which Hcy induces neuronal senescence remains largely unknown. In this study, we observed that Hcy significantly promoted senescence in neuroblastoma 2a (N2a) cells with elevated β-catenin and Kelch-like ECH-associated protein 1 (KEAP1) levels. Intriguingly, Hcy promoted the interaction between KEAP1 and the Wilms tumor gene on the X chromosome (WTX) while hampering the β-catenin-WTX interaction. Mechanistically, Hcy attenuated the methylation level of the KEAP1 promoter CpG island and activated KEAP1 transcription. However, a slow degradation rate rather than transcriptional activation contributed to the high level of β-catenin. Hcy-upregulated KEAP1 competed with β-catenin to bind to WTX. Knockdown of both β-catenin and KEAP1 attenuated Hcy-induced senescence in N2a cells. Our data highlight a crucial role of the KEAP1-β-catenin pathway in Hcy-induced neuronal-like senescence and uncover a promising target for AD treatment.

Recent progress in per- and polyfluoroalkyl substances (PFAS) sensing: A critical mini-review

Per- and polyfluoroalkyl substances (PFAS) are a class of fluorinated pollutants found widely in numerous industrial and consumer products. Their excellent heat, oil, and water resistance and slow degradation rate in nature lead to their persistent environmental accumulation with potential adverse impacts on various organisms, including humans. Although the current EPA-approved PFAS detection method is elegant and ultrasensitive, its broader application is greatly limited due to the associated high costs, lengthy detection times, and skilled personnel requirements. Hence, there is a strong demand for rapid, robust, low-cost, and accessible PFAS detection methods to expedite the treatment of contaminated media and control exposure to these emerging substances. Since the publication of our first PFAS sensing review in 2021, numerous new PFAS sensors have been developed and reported. Consequently, this critical review primarily focuses on recent advancements in PFAS sensing platforms, encompassing optical-based, electrochemical-based, and other novel sensing principle-based systems, as well as those that complement liquid chromatography coupled with tandem mass spectrometry, the gold standard for PFAS detection. The underlying detection mechanisms, sensing performances, and potential areas for improvement are thoroughly discussed. We hope that this article offers readers a review of alternative PFAS detection systems developed in recent years and inspires future innovations in field-deployable PFAS sensing technology.

The Effect of Stereocomplexation and Crystallinity on the Degradation of Polylactide Nanoparticles.

Polymeric nanoparticles (PNPs) are frequently researched and used in drug delivery. The degradation of PNPs is highly dependent on various properties, such as polymer chemical structure, size, crystallinity, and melting temperature. Hence, a precise understanding of PNP degradation behavior is essential for optimizing the system. This study focused on enzymatic hydrolysis as a degradation mechanism by investigation of the degradation of PNP with various crystallinities. The aliphatic polyester polylactide ([C3H4O2]n, PLA) was used as two chiral forms, poly l-lactide (PlLA) and poly d-lactide (PdLA), and formed a unique crystalline stereocomplex (SC). PNPs were prepared via a nanoprecipitation method. In order to further control the crystallinity and melting temperatures of the SC, the polymer poly(3-ethylglycolide) [C6H8O4]n (PEtGly) was synthesized. Our investigation shows that the PNP degradation can be controlled by various chemical structures, crystallinity and stereocomplexation. The influence of proteinase K on PNP degradation was also discussed in this research. AFM did not reveal any changes within the first 24 h but indicated accelerated degradation after 7 days when higher EtGly content was present, implying that lower crystallinity renders the particles more susceptible to hydrolysis. QCM-D exhibited reduced enzyme adsorption and a slower degradation rate in SC-PNPs with lower EtGly contents and higher crystallinities. A more in-depth analysis of the degradation process unveiled that QCM-D detected rapid degradation from the outset, whereas AFM exhibited delayed changes of degradation. The knowledge gained in this work is useful for the design and creation of advanced PNPs with enhanced structures and properties.

Development and Characterization of Gadolinium and Copper Reinforced Bioactive Glass: An In Vitro Study.

Bioactive glass, an innovative alloplastic material utilizing a matrix of silica particles combined with calcium and phosphorus, has been widely employed for the regeneration of bony defects due to its bone-forming capabilities and biocompatibility. Nevertheless, it comes with several drawbacks, including a slow degradation rate, low mechanical strength, and susceptibility to fractures. To address these issues, the present research was done to develop and characterize a novel bioactive glass incorporating gadolinium (Gd) and copper (Cu). The bioactive glass doped with Gd and Cu were synthesized and subjected to characterization through X-ray diffraction (XRD), scanning electron microscopy (SEM), and attenuated total reflectance-infrared (ATR-IR) analysis. The bioactive glass, enriched with Gd and Cu, underwent analysis using ATR-IR spectroscopy, XRD, and SEM. ATR-IR revealed characteristic silicate bands, while SEM indicated the presence of particles larger than 4 μm. XRD analysis identified the formation of Na2Ca4(PO4)2SiO4 (Silicorhenatite), Na2Ca2Si3O9 (Combeite), and wollastonite (calcium inosilicate mineral; CaSiO3). The crystalline nature of these compounds contributed to the favorable mechanical properties of the bioactive glass. In summary, the creation of the innovative Gd-Cu-incorporated bioactive glass demonstrates favorable mechanical characteristics, suggesting significant promise for augmenting bone regeneration.

In vivo assessment of marine vs bovine origin collagen-based composite scaffolds promoting bone regeneration in a New Zealand rabbit model

The ability of human tissues to self-repair is limited, which motivates the scientific community to explore new and better therapeutic approaches to tissue regeneration. The present manuscript provides a comparative study between a marine-based composite biomaterial, and another composed of well-established counterparts for bone tissue regeneration. Blue shark skin collagen was combined with bioapatite obtained from blue shark's teeth (mColl:BAp), while bovine collagen was combined with synthetic hydroxyapatite (bColl:Ap) to produce 3D composite scaffolds by freeze-drying. Collagens showed similar profiles, while apatite particles differed in their composition, being the marine bioapatite a fluoride-enriched ceramic.The marine-sourced biomaterials presented higher porosities, improved mechanical properties, and slower degradation rates when compared to synthetic apatite-reinforced bovine collagen. The in vivo performance regarding bone tissue regeneration was evaluated in defects created in femoral condyles in New Zealand rabbits twelve weeks post-surgery. Micro-CT results showed that mColl:BAp implanted condyles had a slower degradation and an higher tissue formation (17.9 ± 6.9 %) when compared with bColl:Ap implanted ones (12.9 ± 7.6 %). The histomorphometry analysis provided supporting evidence, confirming the observed trend by quantifying 13.1 ± 7.9 % of new tissue formation for mColl:BAp composites and 10.4 ± 3.2 % for bColl:Ap composites, suggesting the potential use of marine biomaterials for bone regeneration.

A review on polylactic acid‐based blends/composites and the role of compatibilizers in biomedical engineering applications

AbstractPoly(lactic acid) (PLA) is one of the most promising biopolymers extensively used in food, packaging, medical and pharmaceutical industries. It is due to favorable physicochemical properties, in‐situ hydrolytic degradation and well‐established processing parameters. However, in medical engineering applications, PLA shows some drawbacks like low cell adhesion, biological inertness, slow degradation rate and high acid inflammation. These shortcomings of pure PLA could be addressed by blending it with other bioresorbable materials and compatibilizers. This review provides comprehensive information on different PLA composites in the field of tissue engineering, implants, injury management and drug delivery systems. The PLA‐based composites are divided into four parts: PLA/polymer, PLA/metal, PLA/ceramic, and PLA/nanoparticles. It also investigates various synthesis process, role of different compatibilizers, in vitro studies and their in vivo applications.Highlights Review the trends of bioresorbable PLA blends/composites. Extensively focused on PLA blend with polymer, metal, ceramic, and nanoparticles. Role of reinforcement and compatibilizer to overcome shortcomings of PLA implant. Highlights advantages, limitations, and properties of different types of PLA implants. Discuss various clinical applications and future of PLA blends/composite scaffolds.

Synergistic effects of photocatalysis-periodate activation system for the degradation of emerging pollutants using GO/MgO nanohybrid

The combination between periodate (PI) activation and photocatalysis processes using heterogeneous catalysts can overcome the slow degradation rates related to photocatalysis and accelerate the degradation of organic pollutants. Thus, a nanohybrid of graphene oxide (GO) and magnesium oxide (MgO) (GO/MgO) was fabricated, characterized, and employed as a photocatalyst and an activator of PI for the degradation of reactive blue-222 (RB-222) dye, sulfamethazine (Sulfonamide antibacterial), and atrazine (Herbicide). Further, the optimization of operating parameters, the stability of the composite, the degradation mechanism, and the effects of water matrices were investigated. The bandgap decreased to 2.6 eV after merging between the GO and MgO, and the separation between charge carriers was improved in the case of the nanohybrid compared to single GO and MgO. The highest degradation percentage of RB-222 dye was achieved under the optimal operating conditions (pH 7, dye concentration of 6.4 mg/L, PI concentration of 1.5 mM, and catalyst dosage of 0.3 g/L) in the presence of light within 120 min. The nanocomposite was reused for five succeeding runs, where the degradation ratios decreased from 97.3% in the first run to 88% in the third run and declined to 81.25% in the fifth run which affirmed the high stability of the catalyst under three succeeding cycles. The degradation mechanism was explored showing that iodate radicals were the main reactive species. The degradation percentages of RB-222 decreased to 85.1% and 67.6% in the case of canal and sea water matrices, respectively. The degradation efficiencies of sulfamethazine and atrazine were 87.5% and 85%, respectively under the optimal conditions. The prepared composite exhibited high degradation performance towards different pollutants which affirmed the applicability of the proposed degradation system for degrading real industrial effluents.

2D Ruthenium-Chromium Oxide with Rich Grain Boundaries Boosts Acidic Oxygen Evolution Reaction Kinetics.

Ruthenium oxide is currently considered as the promising alternative to Ir-based catalysts employed for proton exchange membrane water electrolyzers but still faces the bottlenecks of limited durability and slow kinetics. Herein, a 2D amorphous/crystalline heterophase ac-Cr0.53Ru0.47O2-δ substitutional solid solution with pervasive grain boundaries (GBs) is developed to accelerate the kinetics of acidic oxygen evolution reaction (OER) and extend the long-term stability simultaneously. The ac-Cr0.53Ru0.47O2-δ shows a super stability with a slow degradation rate and a remarkable mass activity of 455AgRu -1 at 1.6V vs RHE, which is ≈3.6- and 5.9-fold higher than those of synthesized RuO2 and commercial RuO2, respectively. The strong interaction of Cr-O-Ru local units in synergy with the specific 2D structural characteristics of ac-Cr0.53Ru0.47O2-δ dominates its enhanced stability. Meanwhile, high-density GBs and the shortened Ru-O bonds tailored by amorphous/crystalline structure and Cr-O-Ru interaction regulate the adsorption and desorption rates of oxygen intermediates, thus accelerating the overall acidic OER kinetics.

Enhanced lignin degradation by Irpex lacteus through expanded sterilization further improved the fermentation quality and microbial community during the silage preservation process

Traditional autoclaving, slow degradation rate and preservation of biomass treated by fungi are the main factors restricting biological treatment. In our previous studies, strains with high efficiency and selective lignin degradation ability were obtained. To further solve the limiting factors of biological treatment, this paper proposed a composite treatment technology, which could replace autoclaves for fungal treatment and improve the preservation and utilization of fungal-pretreated straw. The autoclaved and expanded buckwheat straw were, respectively, degraded by Irpex lacteus for 14 days (CIL, EIL), followed by ensiling of raw materials (CK) and biodegraded straw of CIL and EIL samples with Lactobacillus plantarum for different days, respectively (CP, CIP, EIP). An expansion led to lactic acid bacteria, mold, and yeast of the samples below the detection line, and aerobic bacteria was significantly reduced, indicating a positive sterilization effect. Expansion before I. lacteus significantly enhanced lignin selective degradation by about 6%, and the absolute content of natural detergent solute was about 5% higher than that of the CIL. Moreover, EIL decreased pH by producing higher organic acids. The combination treatment created favorable conditions for ensiling. During ensiling, EIP silage produced high lactic acid about 26.83 g/kg DM and the highest acetic acid about 22.35 g/kg DM, and the pH value could be stable at 4.50. Expansion before I. lacteus optimized the microbial community for ensiling, resulting in EIP silage co-dominated by Lactobacillus, Pediococcus and Weissella, whereas only Lactobacillus was always dominant in CP and CIP silage. Clavispora gradually replaced Irpex in EIP silage, which potentially promoted lactic acid bacteria growth and acetic acid production. In vitro gas production (IVGP) in EIL was increased by 30% relative to CK and was higher than 24% in CIL. The role of expansion was more significant after ensiling, the IVGP in EIP was increased by 22% relative to CP, while that in CIP silage was only increased by 9%. Silage of fungal-treated samples reduced methane emissions by 28% to 31%. The study demonstrated that expansion provides advantages for fungal colonization and delignification, and further improves the microbial community and fermentation quality for silage, enhancing the nutrition and utilization value. This has practical application value for scaling up biological treatment and preserving the fungal-treated lignocellulose.Graphical

Waste to health- seashells and pumpkin seeds into nanohydroxyapatite

Tonnes of pumpkin and piles of sea shells were amassed as waste products every year in the environment. Poor handling of waste can cause environmental pollution and globally initiatives have been made to take of them. Moreover, the focus on turning the waste into useful products hinders the dumping of waste and aids their management. Nanohydroxyapatite, a bioactive bone mineral, has emerged as an ideal candidate for bone substitution applications. The current study focuses on two main goals: waste management and the biogenic preparation of a value-added product, natural nanohydroxyapatite (Nat-Apatite). The seashells and Cucurbita maxima (Pumpkin seeds), which are often discarded as garbage, were utilized as a calcium source and phosphorous source, respectively. The Nat-Apatite exhibited a unique nanoglobular morphology and contained trace elements, such as strontium, magnesium, and sulphur. To assess the degradation rate of Nat-Apatite, we employed electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. The results demonstrated a slow degradation rate, indicating potential compatibility with natural bone remodeling processes. Ex-vivo bone mineralization studies revealed that Nat-Apatite could promote nanoplatelet-like structures on decalcified bone surfaces. Furthermore, our study found that Nat-Apatite effectively enhanced the cell viability. Additionally, MG63 cells treated with Nat-Apatite showed increased production of calcium nodules, collagen, and alkaline phosphatase levels, suggesting improved osteogenic differentiation and bone formation. Thereby, the prepared Nat-Apatite can be potentially employed for biomedical applications.

New modifications of PBAT by a small amount of oxalic acid: Fast crystallization and enhanced degradation in all natural environments

Biodegradable plastics are often mistakenly thought to be capable of degrading in any environment, but their slow degradation rate in the natural environment is still unsatisfactory. We synthetized a novel series of poly(butylene oxalate-co-adipate-co-terephthalate) (PBOAT) with unchanged melting point (135 °C), high elastic modulus (140 - 219 MPa) and elongation at break (478 - 769%). Fast isothermal crystallization with a semi-crystallization time < 20 s was demonstrated by the PBOAT. In N2 and air atmospheres, the PBOAT maintained the Td,5% higher than 329 °C. They also had good thermal stability at melt processing temperature for more than 20 min. PBOAT exhibited faster hydrolysis and seawater degradation, even under natural soil burial without light, but still kept stable under low humidity conditions during the storage and the shelf-life. Moreover, the hydrolysis mechanisms were clarified based on Fukui function analysis and DFT calculation, indicating that the hydrolysis of PBOAT would be more straightforward. The mechanism of soil burial is also elucidated through detailed characterization of the structure changes. The PBOAT offered a fresh approach to the development of high-performing, naturally degradable materials.