Stiff gel-protected fiber-shaped supercapacitors based on CNFA/silk composite fiber with superhigh interference-resistant ability as self-powered temperature sensor.

The development of self-powered sensors with interference-resistant detection is a priority area of research for the next generation of wearable electronic devices. Nevertheless, the presence of multiple stimuli in the actual environment will result in crosstalk with the sensor, thereby hindering the ability to obtain an accurate response to a singular stimulus. Here, we present a self-powered sensor composed of silk-based conductive composite fibers (CNFA@ESF), which is capable of energy storage and sensing. The fabricated CNFA@ESF exhibits excellent mechanical performance, as well as flexibility that can withstand various deformations. The CNFA@ESF provides a good areal capacitance (44.44 mF cm-2), high-rate capability, and excellent cycle stability (91 % for 5000 cycles). In addition, CNFA@ESF also shows good sensing performance for multiple signals including strain, temperature, and humidity. It was observed that the assembly of the symmetrical device with a stiff hydrogel surface layer for protection enabled the real-time, interference-free monitoring of temperature signals. Also, the CNFA@ESF can be woven into fabrics and integrated with a solar cell to form a self-powered sensor system, which has been proven to convert and store solar energy to power electronic watches, indicating its huge potential for future wearable electronics.

In situ growth of curcumin-loaded cellulose composite film for real-time monitoring of food freshness in smart packaging.

Visual pH-responsive packaging material is particularly important in food supply chain safety monitoring due to their non-destructive monitoring method and intuitive result. However, it has always been limited by the instability performance of pH-response components and carriers, which further hinders its wide food safety application. To address these challenges, we selected cellulose with remarkable biocompatibility and mechanical properties as the carrier, and high pH-responsive curcumin to develop a smart packaging material (RC/GC composite film) with real-time food safety monitoring. Compared with pure cellulose film, the RC/GC composite film exhibited excellent mechanical properties (4-fold enhancement) and thermal stability (100 °C increasing). Meanwhile, based on the first reported strategy of curcumin in-situ growth during cellulose film formation, the RC/GC composite film exhibited exceptional antioxidant activity (89.2 %), antimicrobial property (91.6 %), and significant pH-responsive sensitivity (within 15 s). This innovative approach offers a new strategy for easy-to-use and effective monitoring of food spoilage in packaging materials.

Facile synthesis, release mechanism, and life cycle assessment of amine-modified lignin for bifunctional slow-release fertilizer.

Biomass-based slow-release fertilizers (SRFs) are a sustainable solution for addressing food scarcity, improving fertilizer efficiency, and reducing pollution, whereas they still face complex preparation, high costs, and low release characteristics. This study introduces a simple and innovative approach to producing bifunctional green SRFs with controlled release and conditioning properties for saline soils and harsh environments. The method involves a one-pot preparation of microsphere-structured amine-modified lignin slow-release fertilizer (L-UX) using biomass lignin as the starting material. The L-UX demonstrates an exceptional fertilizer loading rate (66.2 %) and extended slow-release performance (288 h), effectively enhancing the fertilizer's release ability. Compared to traditional fertilizers, the bifunctional L-UX significantly improves soil water retention capacity (824.3 %), plant growth, and germination percentage in challenging soil conditions (133 %). These findings highlight the potential of L-UX as a large-scale controlled-release fertilizer in harsh environments. A life cycle assessment (LCA) was also conducted to evaluate the environmental impact of L-UX from its production to disposal. This revealed that L-UX has a minimal environmental footprint compared to conventional inorganic fertilizers. This study further supports the widespread application of L-UX as an environmentally friendly alternative.

Efficient cellulose dissolution and derivatization enabled by oxalic/sulfuric acid for high-performance cellulose films as food packaging.

The performance of cellulose-based materials is highly dependent on the choice of solvent systems. Exceptionally, cellulose dissolution and derivatization by efficient solvent have been considered as a key factor for large-scale industrial applications of cellulose. However, cellulose dissolution and derivatization often requires harsh reaction conditions, high energy consumption, and complex solubilizing, resulting in environmental impacts and low practical value. Here we address these limitations by using a low-temperature oxalic acid/sulfuric acid solvent to enable cellulose dissolution and derivatization for high-performance cellulose films. The dissolution and derivatization mechanism of the mixed acid is studied, demonstrating that cellulose is firstly socked by oxalic acid, then more hydrogen bonds ionized by sulfuric acid break cellulose chain, and finally the esterification reaction between oxalic acid and cellulose is catalyzed by sulfuric acid. Solutions containing 8 %-10 % cellulose are obtained and can be stored for a long time at -18 °C without significant degradation. Moreover, the cellulose film exhibits a higher tensile strength of up to 66.1 MPa, thermal stability, and degree of polymerization compared to that fabricated by sulfuric acid. These unique advantages provide new paths to utilize renewable resources for alternative food packaging materials at an industrial scale.

Two-response surface design optimization of carboxylated CNCs with super high thermal stability and dye removal capability.

Discharging wastewater from industrial dyeing and printing processes poses a significant environmental threat, necessitating green and efficient adsorbents. Cellulose nanocrystals (CNCs) have emerged as a promising option for dye adsorbing. However, the industrial production and commercialization of CNCs still faced low yield, time-consuming, and uneco-friendly. In this study, we proposed a facile hydrochloric/maleic acid (HCl/C4H4O4) hydrolysis method to synthesize carboxylated CNCs using Box-Behnken design and dual response surface design, which can systematically investigate the effect of experimental factors (temperature, time and HCl/C4H4O volume ratio) on the final products. The rod-liked carboxylated CNCs gave the highest yield of 90.50 %, maximum carboxyl content of 1.29 mmol/g, and efficient dye removal ratio of 91.5 %. Furthermore, compared to CNCs obtained by commonly sulfuric acid hydrolysis way (CNCs-S) with a Tmax of 242.6 °C, the CNCs extracted at 5 h exhibited significantly improved thermal stability with Tmax reaching 351.2 °C. The enriched carboxyl content and excellent thermal stability show potential wastewater treatment applications under harsh conditions.

Tailoring Hydronium ion Driven Dissociation-Chemical Cross-Linking for Superfast One-Pot Cellulose Dissolution and Derivatization to Build Robust Cellulose Films.

Concepts of sustainability must be developed to overcome the increasing environmental hazards caused by fossil resources. Cellulose derivatives with excellent properties are promising biobased alternatives for petroleum-derived materials. However, a one-pot route to achieve cellulose dissolution and derivatization is very challenging, requiring harsh conditions, high energy consumption, and complex solubilizing. Herein, we design a one-pot tailoring hydronium ion driven dissociation-chemical cross-linking strategy to achieve superfast cellulose dissolution and derivatization for orderly robust cellulose films. In this strategy, there is a powerful driving force from organic acid with a pKa below 3.75 to dissociate H+ and trigger the dissolution and derivatization of cellulose under the addition of H2SO4. Nevertheless, the driving force can only trigger a partial swelling of cellulose but without dissolution when the pKa of organic acid is above 4.26 for the dissociation of H+ is inhibited by the addition of inorganic acid. The cellulose film has high transmittance (up to ∼90%), excellent tensile strength (∼122 MPa), and is superior to commercial PE film. Moreover, the tensile strength is increased by 400% compared to cellulose film prepared by the ZnCl2 solvent. This work provides an efficient solvent, which is of great significance for emerging cellulose materials from renewable materials.

"Green" electrostatic droplet-assisted forming cellulose microspheres with excellent structural controllability and stability for efficient Cr(VI) removal.

This study presents a novel and environmentally friendly method for producing cellulose microspheres (CM) with controllable morphology and size using electrostatic droplets. The traditional droplet method for CM production requires complex equipment and harmful reagents. In contrast, the proposed method offers a simple electrostatic droplet approach to fabricate CM10 at 10 kV, which exhibited a smaller volume, linear microscopic morphology, and a larger specific surface area, with a 36.60 % improvement compared to CM0 (prepared at 0 kV). CM10 also demonstrated excellent underwater structural stability, recovering in just 0.5 s, and exhibited the highest adsorption capacity for Cr(VI) at 190.16 mg/g, a 72.15 % improvement over CM0. This enhanced adsorption capacity can be attributed to the unique structure of CM10 and the introduction of more amino groups. Moreover, CM10 displayed good cyclic adsorption capacity and high dynamic adsorption efficiency, making it highly suitable for practical applications. CM10 exhibited remarkable adsorption capacity, stability, and practical value in treating Cr(VI) wastewater. This work proposes a simple and eco-friendly method for producing CM with excellent structural controllability and stability, providing an effective route for wastewater treatment.

Deep insights into biodegradability mechanism and growth cycle adaptability of polylactic acid/hyperbranched cellulose nanocrystal composite mulch.

The widespread use of petroleum-based plastic mulch in agriculture has accelerated white and microplastic pollution while posing a severe agroecological challenge due to its difficulty in decomposing in the natural environment. However, endowing mulch film with degradability and growth cycle adaptation remains elusive due to the inherent non-degradability of petroleum-based plastics severely hindering its applications. This work reports polylactic acids hyperbranched composite mulch (PCP) and measured biodegradation behavior under burial soil, seawater, and ultraviolet (UV) aging to understand the biodegradation kinetics and to increase their sustainability in the agriculture field. Due to high interfacial interactions between polymer and nanofiler, the resultant PCP mulch significantly enhances crystallization ability, hydrophilicity, and mechanical properties. PCP mulch can be scalable-manufactured to exhibit modulated degradation performance under varying degradation conditions and periods while concurrently enhancing crop growth (wheat). Thus, such mulch with excellent performance can reduce labor costs and the environmental impact of waste mulch disposal to replace traditional mulch for sustainable agricultural production.

Highly efficient dissolution and reinforcement mechanism of robust and transparent cellulose films for smart packaging.

The packaging of fresh foods increasingly focuses on renewable and eco-friendly cellulose films, but their low dissolution efficiency and weak mechanical strength greatly limit their wide application, which also cannot be used for smart packaging. Here, a highly efficient synergistic chloride-salt dissolution method was proposed to fabricate robust, transparent, and smart cellulose films. Cellulose films with appropriate Ca2+ concentration exhibited robust mechanical strength, better thermal stability, high transparency and crystallinity. The metal chelation of Ca2+ with cellulose chains could induce cellulose chain arrangement during the cellulose regeneration process. Particularly, compared to pure cellulose films, the tensile strength and elongation at break of cellulose films with suitable Ca2+ were increased by 167 % and 200 %, respectively. Moreover, optimal cellulose films can be used to reflect the quality of the fruit by detecting changes in ethanol gas. Hence, a novel strategy is presented to fabricate robust and transparent cellulose films with great potential application for smart packaging.

Next-generation self-adhesive dressings: Highly stretchable, antibacterial, and UV-shielding properties enabled by tannic acid-coated cellulose nanocrystals.

Hydrogels with excellent high-water uptake and flexibility have great potential for wound dressing. However, pure hydrogels without fiber skeleton faced poor water retention, weak fatigue resistance, and mechanical strength to hinder the development of the dressing as next-generation functional dressings. We prepared an ultrafast gelation (6 s) Fe3+/TA-CNC hydrogel (CTFG hydrogel) based on a self-catalytic system and bilayer self-assembled composites. The CTFG hydrogel has excellent flexibility (800% of strain), fatigue resistance (support 60% compression cycles), antibacterial, and self-adhesive properties (no residue or allergy after peeling off the skin). CTFG@S bilayer composites were formed after electrospun silk fibroin (SF) membranes were prepared and adhesive with CTFG hydrogels. The CTFG@S bilayer composites had significant UV-shielding (99.95%), tensile strain (210.9 KPa), and sensitive humidity-sensing properties. Moreover, the integrated structure improved the mechanical properties of electrospun SF membranes. This study would provide a promising strategy for rapidly preparing multifunctional hydrogels for wound dressing.

Multiple noncovalent interactions tailored crystallization and performance reinforcement mechanisms of Biopolyester Composites with functional Cellulose Nanocrystals.

The slow crystallization and weak mechanical features of poly (butylene adipate-co-terephthalate) (PBAT) have become a severe industrial problem in food packaging. Inspired by principle of bionic structure, functional cellulose nanocrystals (CNC) modified with hexamethylene diisocyanate (HMDI) and toluene diisocyanate (TDI) can enhance the crystallization ability and mechanical properties of PBAT nanocomposites. Significantly, CNC-T (CNC modified by TDI) showed a stronger reinforced effect on PBAT properties than unmodified CNCs and CNC-H (CNC modified by HMDI) nanofillers due to hydrogen bonds, π-π interaction between PBAT matrix and CNC-T nanofillers with benzene ring structure. Thus, compared with pure PBAT, PBAT/5CNC-T composites displayed an enhancement of 34.5 % on the tensile strength and exhibited the most robust nucleation ability on PBAT crystallization than CNC and CNC-H. Meanwhile, the possible nucleation, crystallization, and performance reinforcement mechanisms of PBAT nanocomposites have been presented, which is very beneficial for designing robust PBAT nanocomposites with functional cellulose nanocrystals for potential green packaging.

Research on the Role of Innovative Interactive Medical Humanities Education in Standardized Training for Pediatric Residents / 中国医学伦理学

The cultivation of medical humanistic quality is indispensable in the standardized training of pediatric residents, and it is urgent to explore new educational methods to improve their medical humanistic quality level. In this study, 60 standardized pediatricians participated in the standardized training, 36 in the experimental group received innovative interactive medical humanities education, while 24 in the control group were set up to receive traditional medical humanities education. Short-term and long-term test scores were conducted by questionnaire at the beginning of the standardized training and 2 years later. The results showed that there was no significant difference between the experimental group and the control group in the self-scores of professional quality, moral cultivation, communication skills, legal knowledge and innovative spirit (P>0.05) , but the scores of teaching teachers were improved except innovative spirit (P<0.05) . In addition, compared with the control group, the number of pediatricians with professional honor increased, the doctor-patient communication ability improved, the medical disputes reduced, and the family satisfaction improved in experimental group were increased (P<0.05) . These results indicated that innovative interactive medical humanistic education is an effective method to improve the medical humanistic quality of pediatric residents in standardized training.

The Effect of Mitochondrial Damage in Chondrocytes on Osteoarthritis / 生物化学与生物物理进展

The pathogenesis of osteoarthritis (OA) is related to a variety of factors such as mechanical overload, metabolic dysfunction, aging, etc., and is a group of total joint diseases characterized by intra-articular chondrocyte apoptosis, cartilage fibrillations, synovial inflammation, and osteophyte formation. At present, the treatment methods for osteoarthritis include glucosamine, non-steroidal anti-inflammatory drugs, intra-articular injection of sodium hyaluronate, etc., which are difficult to take effect in a short period of time and require long-term treatment, so the patients struggle to adhere to doctor’s advice. Some methods can only provide temporary relief without chondrocyte protection, and some even increase the risk of cardiovascular disease and gastrointestinal disease. In the advanced stages of OA, patients often have to undergo joint replacement surgery due to pain and joint dysfunction. Mitochondrial dysfunction plays an important role in the development of OA. It is possible to improve mitochondrial biogenesis, quality control, autophagy balance, and oxidative stress levels, thereby exerting a protective effect on chondrocytes in OA. Therefore, compared to traditional treatments, improving mitochondrial function may be a potential treatment for OA. Here, we collected relevant literature on mitochondrial research in OA in recent years, summarized the potential pathogenic factors that affect the development of OA through mitochondrial pathways, and elaborated on relevant treatment methods, in order to provide new diagnostic and therapeutic ideas for the research field of osteoarthritis.

Tauroursodeoxycholic acid treats spinal cord injury by reducing apoptosis of spinal cord neurons under glucose and oxygen deprivation / 中国组织工程研究

BACKGROUND:Tauroursodeoxycholic acid is a hydrophilic bile acid derivative that has neuroprotective effects in a variety of neurological disease models.However,there are few reports on the effects of tauroursodeoxycholic acid on spinal cord injury. OBJECTIVE:To investigate the effect of tauroursodeoxycholic acid on apoptosis of spinal cord neurons under hypoglycemic and hypoxic conditions,as well as the effect on recovery of motor function in mice after spinal cord injury. METHODS:(1)In vitro experiment:Primary spinal cord neurons were isolated from C57 BL/6 mouse embryos at 13.5 days of gestation.After 72 hours of culture,the cells were divided into three groups.In the normal group,cells were cultured in Neurobasal complete medium that was incubated in a CO2 incubator(5%CO2 + 95%air)for 24 hours.In the oxyglucose-deprived group,sugar-free Neurobasal medium was added and incubated in a triple-gas incubator(94%N2+5%CO2+1%O2)for 12 hours,and then the medium was replaced with Neurobasal complete medium and incubated in a CO2 incubator for 12 hours.In the experimental group,the treatment procedure was approximately the same as that in the oxyglucose-deprived group,except that taurodeoxycholic acid was added along with the sugar-free Neurobasal medium.TUNEL staining was used to detect apoptosis,cell counting kit-8 assay was applied to detect cell activity,and immunofluorescence staining was performed to detect cellular β-microtubule protein expression.(2)Animal experiment:Sixty C57 BL/6 mice were randomly divided into sham-operated group,spinal cord injury group and experimental group,with 20 mice in each group.Animal models of T9-T10 spinal cord injury were established using Allen's percussion method in the spinal cord injury group and the experimental group.Starting from the 1st day after modeling,taurodeoxycholic acid solution was given by gavage in the experimental group and normal saline was given by gavage in the sham-operated and spinal cord injury groups once a day for 14 consecutive days.Spinal cord tissue repair was assessed using behavioral and histological methods. RESULTS AND CONCLUSION:In vitro experiment:TUNEL staining,cell counting kit-8 and immunofluorescence staining showed that compared with the normal group,the number of apoptotic cells was higher(P＜0.01),while cell activity and β-microtubule protein expression were lower in the oxyglucose-deprived group(P＜0.01);compared with the oxyglucose-deprived group,the number of apoptotic cells was lower(P＜0.01),while cell activity and β-microtubule protein expression were higher in the experimental group(P＜0.01).Animal experiment:The Basso-Beattie-Bresnahan scores in the open field test and hind limb footprint experiments showed that the mice in the experimental group had better recovery of walking and motor functions than those in the spinal cord injury group.Hematoxylin-eosin staining showed that significant deformities and cavities were observed at the site of spinal cord injury and the number of nerve cells was significantly reduced in the spinal cord injury group.Compared with the spinal cord injury group,the experimental group showed a significant reduction in the area of spinal cord injury,less spinal cord deformity,fewer cavities,and an increase in the number of nerve cells.Immunofluorescence staining showed that the number of neuronal nucleus-labeled neuronal cells in the spinal cord injury group was less than that in the sham-operated group(P＜0.01),and the number of neuronal nucleus-labeled neuronal cells in the experimental group was higher than that in the spinal cord injury group(P＜0.01).To conclude,tauroursodeoxycholic acid could effectively reduce glucose/oxygen deprivation-induced apoptosis of spinal cord neurons and axonal loss,and promote the recovery of motor function in mice with spinal cord injury.

Robust and versatile superhydrophobic cellulose-based composite film with superior UV shielding and heat-barrier performances for sustainable packaging.

Replacing single-use plastic delivery bags (SPDBs) with cellulose-based materials is an effective strategy to reduce environmental pollution. However, the inherent hydrophilicity and ultralow mechanical strength of cellulose materials limit its development. In this study, zinc oxide (ZnO)-cellulose composite films were successfully prepared through "two-step strategy" of lotus leaves structure simulation, including deposition of micro-nano ZnO particles and stearic acid (STA) modification. Well-dispersed micro-nano ZnO particles with stick-like structure were anchored in the ZnO-cellulose composite film prepared at 90 °C (CF-90). Due to the special structural design and strong interaction between the cellulose and micro-nano ZnO particles, the CF-90 showed higher mechanical property (a 47.8 % improvement in the tensile strength). Impressively, CF-90 also exhibited great UV shielding properties with larger UPF value of 1603.98 and superhigh heat-barrier performance. Moreover, CF-90 obtained excellent superhydrophobicity with a water contact angle of 163.6° by further modification. Consequently, the versatile cellulose-based material bringing a dawn on application of sustainable packaging materials for express delivery industry.

Multi-functional nanocellulose based nanocomposites for biodegradable food packaging: Hybridization, fabrication, key properties and application.

Nowadays, non-degradable plastic packaging materials have caused serious environmental pollution, posing a threat to human health and development. Renewable eco-friendly nanocellulose hybrid (NCs-hybrid) composites as an ideal alternative to petroleum-based plastic food packaging have been extensively reported in recent years. NCs-hybrids include metal, metal oxides, organic frameworks (MOFs), plants, and active compounds. However, no review systematically summarizes the preparation, processing, and multi-functional applications of NCs-hybrid composites. In this review, the design and hybridization of various NCs-hybrids, the processing of multi-scale nanocomposites, and their key properties in food packaging applications were systematically explored for the first time. Moreover, the synergistic effects of various NCs-hybrids on several properties of composites, including mechanical, thermal, UV shielding, waterproofing, barrier, antimicrobial, antioxidant, biodegradation and sensing were reviewed in detailed. Then, the problems and advances in research on renewable NCs-hybrid composites are suggested for biodegradable food packaging applications. Finally, a future packaging material is proposed by using NCs-hybrids as nanofillers and endowing them with various properties, which are denoted as "PACKAGE" and characterized by "Property, Application, Cellulose, Keen, Antipollution, Green, Easy."

Homogeneous wet-spinning construction of skin-core structured PANI/cellulose conductive fibers for gas sensing and e-textile applications.

Fiber-based wearable electronic textiles have broad applications, but non-degradable substrates may contribute to electronic waste. The application of cellulose-based composite fibers as e-textiles is hindered by the lack of fast and effective preparation methods. Here, we fabricated polyaniline (PANI)/cellulose fibers (PC) with a unique skin-core structure through a wet-spinning homogeneous blended system. The conductive network formation was enabled at a mere 1 wt% PANI. Notably, PC15 (15 wt% PANI) shows higher electrical conductivity of 21.50 mS cm-1. Further, PC15 exhibits excellent ammonia sensing performance with a sensitivity of 2.49 %/ppm and a low limit of detection (LOD) of 0.6 ppm. Cellulose-based composite fibers in this work demonstrate good gas sensing and anti-static properties as potential devices for smart e-textiles.

All-naturally structured tough, ultrathin, and washable dual-use composite for fruits preservation with high biosafety evaluation.

This work develops a sustainable and global strategy to enhance fruit preservation efficacy. The dual-use composite coating or film comprises silk fibroin/cellulose nanocrystals (SF/CNC) with superior ductility through a synergistic plasticizing effect of glycerol and natural aloe-emodin powder (AE) as antimicrobial agents. To confirm our strategy, two common fruit preservation materials (edible surface coating-SCA-CS; packaging film-SCA-PF) and five different fruits (strawberries, bananas, apples, blueberries, and guavas) have been used. Moreover, SCA-CS coating with antibacterial and antioxidant activities formed an ultrathin layer on the fruit's surfaces with a thickness of 7.7 µm and could be easily washable. Therefore, bananas and strawberries' shelf-life with SCA-CS coating can be extended for 9 days and 6 days, respectively. The discharge water of SCA-CS has excellent biosafety in an indoor environment with no threat to plant health (microgreens bean sprouts germination as a case study). The plant exhibited positive results within 15 days, and leaves maintained their green color with a germination rate of 97.6 %. The toughness of SCA-PF film increased by 14,685.7 % with a water vapor transmission rate (WPTR) of 17 g mm m-2 day-1, which confirms that the concept of SCA-PF film and SCA-CS coating are feasible to be used for fruit preservation/packaging.

One-pot strategy to fabricate conductive cellulose nanocrystal-polyethylenedioxythiophene nanocomposite: Synthesis mechanism, modulated morphologies and sensor assembly.

Simple preparation, good conductivity, and excellent hydrophilicity are in urgent demand due to fast growth of wearable intelligent devices. Cellulose nanocrystal-polyethylenedioxythiophene (CNC-PEDOT) nanocomposites with modulated morphology were prepared through Iron (III) p-toluenesulfonate hydrolysis of commercialized microcrystalline cellulose (MCC) and in situ polymerization of 3,4-ethylenedioxythiophene monomers (EDOT) through one-pot green synthesis, where preparation and modification of CNC were obtained for uses as templates to anchor PEDOT nanoparticles. The resultant CNC-PEDOT nanocomposite gave well-dispersed PEDOT nanoparticles with sheet-like structure on the CNC surface, possessing higher conductivity and improved hydrophilicity or dispersibility. Subsequently, a wearable non-woven fabrics (NWF) sensor was successfully assembled by dipping the conductive CNC-PEDOT, and showed excellent sensing response for multiple signals (subtle deformation from various human activities and temperature). This study provides a feasible and large-scale production of CNC-PEDOT nanocomposites and their applications in wearable flexible sensors and electronic devices.

Thermo-sensitive composite microspheres incorporating cellulose nanocrystals for regulated drug release kinetics.

Thermo-sensitive composite microspheres (TPCP) were developed to achieve the on-demand release of drugs. The TPCP microspheres were synthesized using Oil-in-Water (O/W) emulsion evaporation technique and then impregnated with thermo-sensitive polyethylene glycol (PEG). The addition of cellulose nanocrystals (CNCs) significantly enhance thermal stability, crystallization ability, and surface hydrophilicity of TPCP microspheres due to heterogeneous nucleation effect and hydrogen bonding interaction, resulting in stable microsphere structure. The thermal degradation temperature (Tmax) increased by 13.8 °C, and the crystallinity improved by 20.9 % for 10 % TPCP. The thermo-sensitive composite microspheres showed the regulated cumulative release according to in vitro human physiological temperature changes. Besides, four release kinetics and possible release mechanism of TPCP microspheres were provided. Such thermo-responsive composite microspheres with control microsphere sizes and high encapsulation rate may have the potential to the development of on-demand and advanced controlled-release delivery systems.