Preparation and Characterization of Gelatins from Two Sudanese Edible Insects

Gelatins extracted from two edible insects Aspongubus viduatus （melon bug） and Agonoscelis pubescens （sorghum bug） were studied. The two insects showed 27.0 and 28.2% crude protein, respectively. Extraction of gelatin using hot water gave high yield followed by mild acid and distilled water extraction, respectively. SDS-PAGE pattern showed low molecular weight chains, and the two gelatins contained protein with molecular weight of 40 kDa as main component. The differential scanning calorimetry thermograms results confirm no difference between extraction methods concerning the extracted gelatin quality. FTIR spectra of melon and sorghum bug gelatins were similar and the absorption bands were situated in more than 6 bands in melon bug gelatin and only 6 bands in sorghum bug gelatin. Amide II bands of gelatins from both melon and sorghum bug appeared at around 1554 cm^-1, while Amide I bands （1734-1632 cmt） appeared only in melon bug method 2 （MB2） and melon bug method3 （MB3）. Microstructures of the insect gelatin examined with the scanning electron microscope showed that melon bug exhibited the finest gelatin network with very small voids. Melon bug gelatin showed finer structure with smaller protein strands and voids than sorghum bug gelatin.

Tailoring Resorption Rates and Osteogenic Response in Xeno-Hybrid Bone Grafts: The Effect of Added Gelatins

Bone defects resulting from trauma,surgery,congenital malformations,and other factors are among the most common health problems nowadays.Although current strategies such as autografts and allografts are recognized as the most successful treatments for stimulating bone regeneration,limitations such as graft source and complications still exist.SmartBone?is a xeno-hybrid bone graft(made from bovine bone matrix,poly(L-lactic-co-e-caprolactone),and gelatin)with a positive clinical record for bone regen-eration.In this study,the formulation for designing xeno-hybrid bone grafts using gelatins from different sources(bovine-and porcine-derived gelatin,with bone grafts named SBN and SPK,respectively)was investigated,and the biological responses were evaluated in vitro and in vivo.The results demonstrate that gelatins from both bovine and porcine sources can be loaded onto SmartBone?successfully and safely,withstanding the aggressive manufacturing processes.Different bone cell responses were observed in vitro.SBN was found to enhance osteocalcin secretion while SPK was found to upregulate osteopontin from human osteoblasts.In vivo,both bone grafts promoted osteogenesis,but SPK degraded earlier than SBN.Our findings suggest that SBN and SPK provide different yet comparable solutions for optimizing the bone resorption and regeneration balance.These xeno-hybrid bone grafts possess ideal potential for bone defect repairing.

One-step cell biomanufacturing platform:porous gelatin microcarrier beads promote human embryonic stem cell-derived midbrain dopaminergic progenitor cell differentiation in vitro and survival after transplantation in vivo

Numerous studies have shown that cell replacement therapy can replenish lost cells and rebuild neural circuitry in animal models of Parkinson’s disease.Transplantation of midbrain dopaminergic progenitor cells is a promising treatment for Parkinson’s disease.However,transplanted cells can be injured by mechanical damage during handling and by changes in the transplantation niche.Here,we developed a one-step biomanufacturing platform that uses small-aperture gelatin microcarriers to produce beads carrying midbrain dopaminergic progenitor cells.These beads allow midbrain dopaminergic progenitor cell differentiation and cryopreservation without digestion,effectively maintaining axonal integrity in vitro.Importantly,midbrain dopaminergic progenitor cell bead grafts showed increased survival and only mild immunoreactivity in vivo compared with suspended midbrain dopaminergic progenitor cell grafts.Overall,our findings show that these midbrain dopaminergic progenitor cell beads enhance the effectiveness of neuronal cell transplantation.

Three-dimensional porous bimetallic metal–organic framework/gelatin aerogels: A readily recyclable peroxymonosulfate activator for efficient and continuous organic dye removal

As promising catalysts for the degradation of organic pollutants,metal–organic frameworks(MOFs)often face limitations due to the particle agglomeration and challenging recovery in liquid-catalysis application,stemming from their powdery nature.Engineering macroscopic structures from pulverous MOF is thus of great importance for broadening their practical applications.In this study,three-dimensional porous MOF aerogel catalysts were successfully fabricated for degrading organic dyes by activating peroxymonosulfate(PMS).MOF/gelatin aerogel(MOF/GA)catalysts were prepared by directly integrating bimetallic FeCo-BDC with gelatin solutions,followed by freeze-drying and low-temperature calcination.The FeCo-BDC-0.15/GA/PMS system exhibited remarkable performance in degrading various organic dyes,eliminating 99.2%of rhodamine B within a mere 5 min.Compared to the GA/PMS system,there was over a 300-fold increase in the reaction rate constant.Remarkably,high removal efficiency was maintained across varying conditions,including different solution pH,co-existing inorganic anions,and natural water matrices.Radical trapping experiments and electron paramagnetic resonance analysis revealed that the degradation involved radical(SO_(4)^(-)·)and non-radical routes(^(1)O_(2)),of which ^(1)O_(2) was dominant.Furthermore,even after a continuous 400-min reaction in a fixed-bed reactor at a liquid hourly space velocity of 27 h^(-1),the FeCo-BDC/GA composite sustained a degradation efficiency exceeding 98.7%.This work presents highly active MOF-gelatin aerogels for dye degradation and expands the potential for their large-scale,continuous treatment application in organic dye wastewater management.

Bio-inspired Hydroxyapatite/Gelatin Transparent Nanocomposites

Hydroxyapatite(HA)nanoparticles impart outstanding mechanical properties to organicinorganic nanocomposites in bone.Inspired by the composite structure of HA nanoparticles and collagen in bone,a high performance HA/gelatin nanocomposite was first developed.The nanocomposites have much better mechanical properties(elongation at break 29.9%,tensile strength 90.7 MPa,Young’s modulus 5.24 GPa)than pure gelatin films(elongation at break 9.3%,tensile strength 90.8 MPa,Young’s modulus 2.5 GPa).In addition,the composite films keep a high transmittance in visible wavelength range from 0%to 60%of the HA solid content.These differences in properties are attributed to the homogeneous distribution of HA nanoparticles in the gelatin polymer matrix and the strong interaction between the particle surfaces and the gelatin molecules.This protocol should be promising for HA-based nanocomposites with enhanced mechanical properties for biomedical applications.

Experimental clearance rate and intraguild predation of jellyfish Cyanea nozakii

Cyanea nozakii,a common jellyfish distributed in offshore China,has a complex trophic relationship with other zooplankton groups.However,few studies have reported the predation rates and prey selection patterns of C.nozakii medusae on different prey items.Research is also lacking on the intraguild predation of Aurelia coerulea(another common bloom jellyfish in offshore China)by C.nozakii.To address the knowledge gaps,the clearance rates of C.nozakii for different prey items,including copepods(small<1000μm and large>1000μm),fish larvae,and gelatinous prey(hydromedusae,A.coerulea ephyrae,and chaetognaths),were measured.The influence of predator size on the clearance rate was also determined.Additionally,we examined the intraguild predation of C.nozakii on A.coerulea medusae.The clearance rates of C.nozakii varied widely with prey organisms,being independent of prey concentrations.Gelatinous organisms,except for chaetognaths,were captured with considerably high efficiency,followed by fish larvae and copepods,indicating the preferential prey selection of gelatinous organisms by C.nozakii.The clearance rate increased linearly with the cross-sectional area of C.nozakii.Body size in medusae may,to some extents,underpin their capacity to capture more prey by increasing the encounter rate and capture success through ontogeny.C.nozakii preyed voraciously on A.coerulea in high feeding efficiency,but the clearance rate decreased with increasing A.coerulea(as prey)size.This phenomenon of intraguild predation suggests a speculative hypothesis of potential population regulation of A.coerulea by C.nozakii.The information regarding the feeding ecology of C.nozakii reported in this study is important for understanding plankton dynamics in marine ecosystems with extensive occurrences of this jellyfish.

Constructing a biofunctionalized 3D-printed gelatin/sodium alginate/chitosan tri-polymer complex scaffold with improvised biological andmechanical properties for bone-tissue engineering

Sodium alginate(SA)/chitosan(CH)polyelectrolyte scaffold is a suitable substrate for tissue-engineering application.The present study deals with further improvement in the tensile strength and biological properties of this type of scaffold to make it a potential template for bone-tissue regeneration.We experimented with adding 0%–15%(volume fraction)gelatin(GE),a protein-based biopolymer known to promote cell adhesion,proliferation,and differentiation.The resulting tri-polymer complex was used as bioink to fabricate SA/CH/GEmatrices by three-dimensional(3D)printing.Morphological studies using scanning electron microscopy revealed the microfibrous porous architecture of all the structures,which had a pore size range of 383–419μm.X-ray diffraction and Fourier-transform infrared spectroscopy analyses revealed the amorphous nature of the scaffold and the strong electrostatic interactions among the functional groups of the polymers,thereby forming polyelectrolyte complexes which were found to improve mechanical properties and structural stability.The scaffolds exhibited a desirable degradation rate,controlled swelling,and hydrophilic characteristics which are favorable for bone-tissue engineering.The tensile strength improved from(386±15)to(693±15)kPa due to the increased stiffness of SA/CH scaffolds upon addition of gelatin.The enhanced protein adsorption and in vitro bioactivity(forming an apatite layer)confirmed the ability of the SA/CH/GE scaffold to offer higher cellular adhesion and a bone-like environment to cells during the process of tissue regeneration.In vitro biological evaluation including the MTT assay,confocal microscopy analysis,and alizarin red S assay showed a significant increase in cell attachment,cell viability,and cell proliferation,which further improved biomineralization over the scaffold surface.In addition,SA/CH containing 15%gelatin designated as SA/CH/GE15 showed superior performance to the other fabricated 3D structures,demonstrating its potential for use in bone-tissue engineering.

Rice Grains from Slightly Saline Field Exhibited Unchanged Starch Physicochemical Properties but Enhanced Nutritional Values

This study aims to investigate grain quality and nutritional values of rice(Pokkali,a salt-tolerant cultivar;RD73,a new cultivar improved from KDML105 introgressed with Saltol QTL from Pokkali,and KDML105,a moderately salt-susceptible cultivar)grown under non-saline(0.04–0.87 dS/m)and slightly saline(1.08–4.83 dS/m)field conditions.The results revealed that salinity caused significant reduction in grain size but significant increments in reducing sugar and total protein contents in the grains.Nevertheless,the amounts of starch in the grains of KDML105 and Pokkali rice genotypes were unaffected by the stress.The starch granule size distribution was also unaffected by salinity.Interestingly,only starch from Pokkali was significantly diminished in amylose content,from 19.18%to 16.99%.Accordingly,parameters relating to starch gelatinization,retrogradation,and pasting properties of KDML105 and RD73 were unaffected by salinity;only Pokkali showed a significant increase in percentage of retrogradation along with a significant reduction in gelatinization enthalpy.In the saline field,total phenolic content and antioxidant capacity in the grains of all rice cultivars tended to increase,particularly in Pokkali.On average,essential element contents in grains from the saline-treated plants showed a 33%,32%,32%,22%,20%,11%,and 10%increase in total P,N,K,Mg,Zn,Fe,and Ca content,respectively.Interestingly,total Fe content exhibited the greatest percentage of increments in KDML105(187%).Taken together,cultivation of rice in the slightly saline field did not alter its eating and cooking qualities,while enhanced some nutritional properties such as proteins,minerals,and secondary metabolites like phenolic compounds.

Fish Gelatin-Based Film Containing Maillard Reaction Products:Properties and Its Use as Bag for Packing Chicken Skin Oil

Maillard reaction is a non-enzymatic browning reaction and its products(MRPs)have been proven to possess antioxidant properties.This research aimed to produce a fish gelatin-based packaging incorporated with MRPs to retard lipid oxidation in chicken skin oil(CSO)during storage at ambient temperature(28℃–30℃).MRPs produced from fish gelatin and fructose(1:1,90℃,pH 11)showed the highest antioxidant properties compared to those prepared under other conditions.Different glycerol/MRPs ratios(30:0,25:5,20:10,15:15,10:20,5:25,0:30)were incorporated into the film and resulting films were characterized.Glycerol/MRPs at 10:20 ratio was chosen to add into the film prior to bag preparation via heat sealing method.CSO packed in the bag was monitored for lipid hydrolysis and oxidation during 15 days of storage(30℃±0.5℃,RH 52%±5%).After 15 days,quality deterioration was lower in CSO packed in the prepared gelatin bag as evidenced by lower FFA,TBARS,and volatile compounds in comparison with CSO packed in LDPE bag.Fish gelatin film added with MRPs possessed an excellent water vapor barrier property(WV-BP).This finding indicated that MRPs could be used to substitute glycerol and simultaneously could serve as antioxidants for the developed active bag.The novel packaging can be a potential alternative packaging for retarding lipid oxidation of lipid or fatty foods.

Effect of Butternut Squash (Cucurbita moschata) Seed Powder on the Chemical and Rheological Properties of Stirred Cultured Camel Milk and Yoghurt

Research shows that producing fermented camel milk is hard because of the milk’s inability to form a firm coagulum, attributed to low levels of κ-casein and ꞵ-lactoglobulin and the large casein micelle size, leading to a weak network of casein formation. In an effort to address this issue, researchers turned to corn starch as a thickening agent, discovering that a concentration of 2.0% effectively improved the viscosity and significantly reduced syneresis in stirred camel milk yoghurt and cultured camel milk. This study explores alternatives to corn starch, focusing on butternut squash seeds as a promising substitute due to their hydrocolloid composition. By incorporating butternut squash (Cucurbita moschata) seed powder (BSSP) as a thickening agent, this study aimed at enhancing the chemical and rheological properties of stirred camel milk yoghurt and cultured camel milk. Fermented camel milk was prepared using 4 litres of camel milk, 2% starter cultures (thermophilic culture for yoghurt and mesophilic aromatic culture for stirred cultured camel milk) and BSSP 0.0% (negative control), 0.4%, 0.8%, 1.2%, 1.6%, 2.0% mixed with 0.4% gelatin. 2.0% corn starch mixed with 0.4% gelatin was used as a standard for comparison. Results showed that increasing the BSSP level significantly (p < 0.05) decreased the moisture content while increasing the total solid content of stirred fermented camel milk products. There was an increase in ash content with an increase in BSSP levels. There was a significant (p < 0.05) reduction in the pH, with an increase in BSSP levels in stirred fermented camel milk samples. Increasing the concentration of BSSP from 0.4% to 2.0% resulted in a significant (p < 0.05) increase in viscosity and a reduction in syneresis of stirred camel milk yoghurt and stirred cultured camel milk samples. This study demonstrated that BSSP effectively enhances the viscosity, reduces syneresis and increases acidity in stirred fermented camel milk products during storage.

Studies of XRD and FTIR on Synthesized Novel Hybrid Thin Film Made of Hydroxyapatite, Poly Vinyl Alcohol and Gelatin for Biomedical Application

With the modern advancement of treatment approaches in medical science, the application of biomaterials in tissue engineering provides a remarkable opportunity to overcome graft rejection as well as proper wound healing. In this study, novel hybrid films have been synthesized by incorporation of polyvinyl alcohol (PVA), gelatin, and gelatin with glycerin along with different concentrations of pre-prepared hydroxyapatite (HAP) by solution casting method at room temperature in a biosafety cabinet. Glutaraldehyde has been added as a crosslinker in this whole procedure. Fourier-transform infrared spectroscopy (FTIR), X-Ray Diffraction (XRD) have been conducted to observe and compare the structural and chemical stability of the synthesized hybrid film properties. The FTIR results and X-Ray Diffraction analyses confirmed the chemical interactions between HAP, PVA, gelatin, and glycerin have occurred. The crystallinity of HAP also remains in all the prepared hybrid film samples that are observed in XRD. It is expected that these newly synthesized hybrid films could be a better opportunity for various sectors of tissue engineering such as skin, bone, tendon, and cartilage. These synthesized hybrid films can be suitable for wound healing covering. These studies could be a new scope for long-term drug delivery directly on wound sites in diabetic gangrene foot or burn patients as well as cartilage or joint replacement therapy.

Development and Characterization of Hybrid Film Made of Hydroxyapatite, Poly Vinyl Alcohol and Gelatin for Biomedical Application

In the recent research field of bone tissue engineering, polymeric materials play an implacable role in mimes the natural behavior of hard and soft tissues. In some medical conditions such as diabetics, osteoarthritis, burns, or joint replacement conditions, this polymeric materials implication enhances the internal mechanical activities which result in the early recovery of disease by facilitating the wound healing process. In this study, hybrid films have been synthesized based on polyvinyl alcohol (PVA), gelatin, and gelatin with glycerin incorporated with different concentrations of pre-prepared hydroxyapatite (HAP) by solution casting method at room temperature in biosafety cabinet. Glutaraldehyde has been added as a crosslinker in this whole procedure. The mechanical property, swelling, and porosity percentage have been conducted to characterize the structural stability of the synthesized hybrid films. Porosity and swelling of samples are also represented by proper biocompatibility (>90% porosity and swelling in DDW and PBF vary between 287%~72%). Tensile strength (TS), E modulus (Young’s modulus), Elongation at maximum, and Elongation at break are observed to perceive the mechanical properties of hybrid film samples, which are compatible with mechanical properties of different tissue such as trabecular bone, articular cartilage, tendon, nerve and skin tissue. Though, biocompatibility tests both in vivo and in vitro are essential for clinical application in the future. However, the experiment carried out till now explains the true possibility of newly synthesized hybrid films for long-term drug delivery directly on wound sites for wound healing and burn dressing patients in head-neck surgery reconstruction, diabetic gangrene foot, as well as cartilage or joint replacement therapy.

Tissue Regeneration in Infected Wounds of Albino Rats Using Ciprofloxacin-Loaded Gelatin Microspheres Incorporated Collagen Scaffold: A Histological Approach with H&E Staining

A wound care system consisting of ciprofloxacin-loaded gelatin microspheres impregnated in a macroporous collagen scaffold was created to effectively control wound infection and regenerate soft tissue at the wound site.Histological and biochemical alterations were observed in infected wounds treated with these scaffolds in Albino Wistar rats.Furthermore,the study examined the immediate and prolonged release of ciprofloxacin from the scaffolds,as well as their function in eliminating bacterial infections and expediting the process of skin healing and regeneration.The developed technique was followed in the streamlined process of creating these collagen scaffolds.Compared to untreated wounds,the group receiving scaffold treatment experienced a faster rate of wound closure.It was noted that the rate of infections was considerably reduced and that full soft tissue regeneration occurred within 12 days.The development of well-deposited collagen bundles in the treated groups was demonstrated by H&E staining,which verified the flawless regeneration of the dermis and epidermis.The antimicrobial agent-loaded gelatin microspheres impregnated into the porous collagen scaffold demonstrated remarkable soft tissue regeneration and efficient infection control at the wound site.

Antibacterial Chitosan-Gelatin Microcapsules Modified with Green-Synthesized Silver Nanoparticles for Food Packaging

Silver nanoparticles(Ag NPs)are an effective antibacterial agent,but their application in food packaging is limited due to their easy agglomeration and oxidation.In this study,antibacterial microcapsules were fabricated using Ginkgo biloba essential oil(GBEO)as core material and chitosan and type B gelatin biopolymer as capsule mate-rials.These antibacterial microcapsules were then modified with green-synthesized Ag NPs,blended into the bio-polymer polylactic acid(PLA),and finally formed as films.Physicochemical properties and antibacterial activity against Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)were evaluated.Results showed that the prepared antibacterial PLA films exhibited excellent antibacterial activity against foodborne pathogens.Its TVC exceeded the limit value of 7 log CFU/g at 7 days compared with the 5 days of pure PLA films.Therefore,these films can extend the shelf life of grass carp fillets by 2–3 days under refrigeration.

Evaluation of different crosslinking methods in altering the properties of extrusion-printed chitosan-basedmulti-material hydrogel composites

Three-dimensional printing technologies exhibit tremendous potential in the advancing fields of tissue engineering and regenerative medicine due to the precise spatial control over depositing the biomaterial.Despite their widespread utilization and numerous advantages,the development of suitable novel biomaterials for extrusion-based 3D printing of scaffolds that support cell attachment,proliferation,and vascularization remains a challenge.Multi-material composite hydrogels present incredible potential in this field.Thus,in this work,a multi-material composite hydrogel with a promising formulation of chitosan/gelatin functionalized with egg white was developed,which provides good printability and shape fidelity.In addition,a series of comparative analyses of different crosslinking agents and processes based on tripolyphosphate(TPP),genipin(GP),and glutaraldehyde(GTA)were investigated and compared to select the ideal crosslinking strategy to enhance the physicochemical and biological properties of the fabricated scaffolds.All of the results indicate that the composite hydrogel and the resulting scaffolds utilizing TPP crosslinking have great potential in tissue engineering,especially for supporting neo-vessel growth into the scaffold and promoting angiogenesis within engineered tissues.

3D printing of personalized polylactic acid scaffold laden with GelMA/autologous auricle cartilage to promote ear reconstruction

At present,the clinical reconstruction of the auricle usually adopts the strategy of taking autologous costal cartilage.This method has great trauma to patients,poor plasticity and inaccurate shaping.Three-dimensional(3D)printing technology has made a great breakthrough in the clinical application of orthopedic implants.This study explored the combination of 3D printing and tissue engineering to precisely reconstruct the auricle.First,a polylactic acid(PLA)polymer scaffold with a precisely customized patient appearance was fabricated,and then auricle cartilage fragments were loaded into the 3D-printed porous PLA scaffold to promote auricle reconstruction.In vitro,gelatin methacrylamide(GelMA)hydrogels loaded with different sizes of rabbit ear cartilage fragments were studied to assess the regenerative activity of various autologous cartilage fragments.In vivo,rat ear cartilage fragments were placed in an accurately designed porous PLA polymer ear scaffold to promote auricle reconstruction.The results indicated that the chondrocytes in the cartilage fragments could maintain the morphological phenotype in vitro.After three months of implantation observation,it was conducive to promoting the subsequent regeneration of cartilage in vivo.The autologous cartilage fragments combined with 3D printing technology show promising potential in auricle reconstruction.

Enhanced wound healing and hemostasis with exosome-loaded gelatin sponges from human umbilical cord mesenchymal stem cells

BACKGROUND Rapid wound healing remains a pressing clinical challenge,necessitating studies to hasten this process.A promising approach involves the utilization of human umbilical cord mesenchymal stem cells(hUC-MSCs)derived exosomes.The hypothesis of this study was that these exosomes,when loaded onto a gelatin sponge,a common hemostatic material,would enhance hemostasis and accelerate wound healing.AIM To investigate the hemostatic and wound healing efficacy of gelatin sponges loaded with hUC-MSCs-derived exosomes.METHODS Ultracentrifugation was used to extract exosomes from hUC-MSCs.Nanoparticle tracking analysis(NTA),transmission electron microscopy(TEM),and western blot techniques were used to validate the exosomes.In vitro experiments were performed using L929 cells to evaluate the cytotoxicity of the exosomes and their impact on cell growth and survival.New Zealand rabbits were used for skin irritation experiments to assess whether they caused adverse skin reactions.Hemolysis test was conducted using a 2%rabbit red blood cell suspension to detect whether they caused hemolysis.Moreover,in vivo experiments were carried out by implanting a gelatin sponge loaded with exosomes subcutaneously in Sprague-Dawley(SD)rats to perform biocompatibility tests.In addition,coagulation index test was conducted to evaluate their impact on blood coagulation.Meanwhile,SD rat liver defect hemostasis model and full-thickness skin defect model were used to study whether the gelatin sponge loaded with exosomes effectively stopped bleeding and promoted wound healing.RESULTS The NTA,TEM,and western blot experimental results confirmed that exosomes were successfully isolated from hUC-MSCs.The gelatin sponge loaded with exosomes did not exhibit significant cell toxicity,skin irritation,or hemolysis,and they demonstrated good compatibility in SD rats.Additionally,the effectiveness of the gelatin sponge loaded with exosomes in hemostasis and wound healing was validated.The results of the coagulation index experiment indicated that the gelatin sponge loaded with exosomes had significantly better coagulation effect compared to the regular gelatin sponge,and they showed excellent hemostatic performance in a liver defect hemostasis model.Finally,the full-thickness skin defect healing experiment results showed significant improvement in the healing process of wounds treated with the gelatin sponge loaded with exosomes compared to other groups.CONCLUSION Collectively,the gelatin sponge loaded with hUC-MSCs-derived exosomes is safe and efficacious for promoting hemostasis and accelerating wound healing,warranting further clinical application.

Viscosity reduction of tapioca starch by incorporating with molasses hydrocolloids

As a low cost non-staple food resource,the high-viscosity paste and poor gel-forming ability of tapioca starch limit its industrial application.Herein,molasses hydrocolloids that is a by-product of the sugar refining process was applied as a blending modifier to reduce the viscosity of tapioca starch paste.The test results of paste and rheological properties show that molasses hydrocolloids exhibited a good physical viscosity-reducing effect on tapioca starch paste.The irregular network structure and high K^(+)/Ca^(2+)ion contents of molasses hydrocolloids exerted wrapping,adhesion,barrier,and hydration effects on starch,leading to the reduction of viscosity.The scanning electron microscope images and textural analysis demonstrated that this strategy also improve the structure of tapioca starch gel and enhanced its puncture strength by 75.46%.This work shows the great potential of molasses hydrocolloids as a lowcost and desirable material for the viscosity reduction of tapioca starch.

3D-printed engineered bacteria-laden gelatin/sodium alginate composite hydrogels for biological detection of ionizing radiation

Nuclear safety is a global growing concern,where ionizing radiation(IR)is a major injury factor resulting in serious damage to organisms.The detection of IR is usually conducted with physical dosimeters;however,biological IR detection methods are deficient.Here,a living composite hydrogel consisting of engineered bacteria and gelatin/sodium alginate was 3D-printed for the biological detection of IR.Three strains of PrecA::egfp gene circuit-containing engineered Escherichia coli were constructed with IR-dependent fluorescence,and the DH5αstrain was finally selected due to its highest radiation response and fluorescence.Engineered bacteria were loaded in a series of gelatin/sodium alginate matrix hydrogels with different rheology,3D printability and bacterial applicability.A high-gelatin-content hydrogel containing 10%gelatin/1.25%sodium alginatewas optimal.The optimal living composite hydrogelwas 3D-printedwith the special bioink,which reported significant green fluorescence underγ-ray radiation.The living composite hydrogel provides a biological strategy for the detection of environmental ionizing radiation.

Alginate/gelatin/boron-doped hydroxyapatite-coated Ti implants:in vitro and in vivo evaluation of osseointegration

In this study,boron-doped hydroxyapatite(BHT)-loaded alginate/gelatin-based(A/G)hydrogel coating on Ti was fabricated to support bone integration through triggering osteoinduction,vascularization and immunomodulation.Initially,highly reproducible,cheap and time-effective BHT was produced,which significantly promoted higher osteogenic and angiogenic maturation,while a mild innate immune response was observed.The immense potential of BHT was evidenced by the production of a gap-filling A/G/BHT interphase on Ti implants to mimic the osseous extracellular matrix to achieve functional bridging and exert control over the course of innate immune response.We initially aminosilanized the implant surface using 3-aminopropyl triethoxysilane,and then coated it with 0.25%w/v alginate with 20 mM 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide to allowthe A/G/BHT pre-gel to disperse evenly and covalently attach on the surface.The pre-gel was added with 0.2 M NaCl to homogeneously blend BHT in the structure without inducing ionic crosslinking.Then,the coated implants were freeze-dried and stored.The coated layer demonstrated high cohesive and adhesive strength,and 8-month-long shelf-life at room temperature and normal humidity.The A/G/BHT was able to coat an irregularly shaped Ti implant.Osteoblasts and endothelial cells thrived on the A/G/BHT,and it demonstrated greatly improved osteogenic and angiogenic capacity.Moreover,A/G/BHT maintained macrophage viability and generated an acute increase in immune response that could be resolved rapidly.Finally,A/G/BHT was shown to induce the robust integration of implant in a rabbit femur osteochondral model within 2months.Therefore,we concluded that A/G/BHT coatings could serve as amultifunctional reservoir,promoting the strong and rapid osseointegration of metallic implants.