Biodegradable Polymer Matrix Research Articles

High performance flexible green triboelectric nanogenerator with polyethylene oxide/mica tribo-positive composite material

Innovating novel, green, biodegradable, and recyclable polymers are critical for the development of environmentally sustainable solutions, eliminating concerns of pollution and microplastic accumulation. Herin, this study presents remarkably enhanced tribo-positive polyethylene oxide (PEO) polarity, by incorporating for the first time, a clay inorganic filler, creating a novel biodegradable composite triboelectric material. The low-cost composite comprised a biodegradable polymeric PEO matrix, an abundant naturally sourced muscovite mica micro-platelet filler, and integrated simple material fabrication methods. A 4 cm2 PEO/Mica film was paired with polytetrafluoroethylene (PTFE), generating a peak-to-peak voltage, current density, and transferred charge density of respectfully, 296 V, 24.2 mA m−2, and 110.3 µC m−2. Reducing the film thickness to 40 µm dramatically enhanced the electrical output, resulting in a peak-to-peak voltage and instantaneous power density of respectfully, 424 V and 12.1 W m−2. The addition of mica greatly improved the dielectric permittivity, promoting the outstanding triboelectric performance. The composite material's long-term stability and flexibility demonstrated significant advantages for self-powering small electronic systems. Furthermore, PEOs facile water solubility allowed mica separation, recovery, recyclability, and integration within new PEO/Mica films, resulted in preserved triboelectric outputs. The PEO/Mica composite delivers exceptional sustainable, recyclable, and tribo-positive attributes, serving as an excellent energy harvesting solution.

Characterization of Calotropis gigantiea plant leaves biomass-based bioplasticizers for biofilm applications

The present surge in environmental consciousness has pushed for the use of biodegradable plasticizers, which are sustainable and abundant in plant resources. As a result of their biocompatibility and biodegradability, Calotropis gigantiea leaf plasticizers (CLP) serve as viable alternatives to chemical plasticizers. First time, the natural plasticizers from the Calotropis leaves were extracted for this study using a suitable chemical approach that was also environmentally friendly. The XRD results showed a reduced crystallinity index of 20.2 % and a crystalline size of 5.3 nm, respectively. TGA study revealed that the CLP has good thermal stability (244 °C). Through FT-IR study, the existence of organic compounds in CLP can be investigated by key functional groups such as alcohol, amine, amide, hydrocarbon, alkene, aromatic, etc. Further the presence of alcoholic, amino, and carboxyl constituents was confirmed by UV investigation. SEM, EDAX analysis, and AFM are used to examine the surface morphology of the isolated plasticizer. SEM pictures reveal rough surfaces on the CLP surface pores, which makes them suitable for plasticizing new bioplastics with improved mechanical properties. Poly (butylene adipate-co-terephthalate) (PBAT), a biodegradable polymer matrix, was used to investigate the plasticization impact after the macromolecules were characterised. The biofilm PBAT/CLP had a thickness of 0.8 mm. In addition, the reinforcement interface was examined using scanning electron microscopy. When CLP is loaded differently in PBAT, the tensile strength and young modulus change from 15.30 to 24.60 MPa and from 137 to 168 MPa, respectively. CLP-reinforced films demonstrated better surface compatibility and enhanced flexibility at a loading of 2 % when compared to pure PBAT films. Considering several documented characteristics, CLP may prove to be an excellent plasticizer for resolving environmental issues in the future.

A hollow magnetic soft robot consisting of rod-shaped nanofiber actuators

Magnetic soft robots are prominent in biological environments due to the untethered movement and penetration under magnetic field. Moreover, in order to overcome biological barriers in microenvironment, the development of small size, biocompatible/biodegradable and precisely controlled mobility of magnetic soft robots is a promising. Thus, a hollow magnetic soft robot consisting of rod-shaped nanoactuators formed by the cleavage of photosensitive electrospun nanofibers is designed. The nanofiber actuators are composed of biodegradable polymer matrix and biocompatible superparamagnetic magnetic iron oxide nanoparticle fillers, and the uniform rod-shaped nanofibers are obtained from the molecule fracture of photosensitive copolymers under UV irradiation. Based on the bottom-up and top-down constructing concept, the hollow magnetic soft robots show unique property of the stabilized morphology, the programmed magnetization and the high order motion transition in an instant. This provides a strategy for designing and obtaining the adaptive magnetic soft robots, which can effectively improve the precise locomotion and fast movement efficiency in complex physiological environment.

Processing of Thin Films Based on Cellulose Nanocrystals and Biodegradable Polymers by Space-Confined Solvent Vapor Annealing and Morphological Characteristics.

L-poly(lactic acid), poly(3-hydroxybutyrate), and poly-hydroxybutyrate-co-hydroxyvalerate are biodegradable polymers that can be obtained from renewable biomass sources. The aim of this study was to develop three types of environmentally friendly film biocomposites of altered microstructure by combining each of the above-mentioned polymers with cellulose nanocrystal fillers and further processing the resulting materials via space-confined solvent vapor annealing. Cellulose was previously obtained from renewable biomass and further converted to cellulose nanocrystals by hydrolysis with the lactic acid. The solutions of biodegradable polymers were spin-coated onto solid substrates before and after the addition of cellulose nanocrystals. The obtained thin film composites were further processed via space-confined solvent vapor annealing to eventually favor their crystallization and, thus, to alter the final microstructure. Indeed, atomic force microscopy studies have revealed that the presence of cellulose nanocrystals within a biodegradable polymer matrix promoted the formation of large crystalline structures exhibiting fractal-, spherulitic- or needle-like morphologies.

Isolation and characterization of novel bioplasticizers from rose (Rosa damascena Mill.) petals and its suitability investigation for poly (butylene adipate-co-terephthalate) biofilm applications.

The current growing environmental awareness has forced the use of biodegradable plasticizers, which are sustainable and abundant in plant resources. Rose petal plasticizers (RPP) act as an actual substitute for chemical plasticizers in this situation as they are biocompatible and biodegradable. Chemical procedures like amination, alkalization, and surface catalysis are used to extract the natural emollients from rose petals. XRD, FT-IR, and UV studies were used to understand the characteristics of the rose petal plasticizer. Based on the XRD data, the RPP's crystallinity size (CS) and crystallinity index (CI) values were determined to be 9.36nm and 23.87%, respectively. The surface morphology of the isolated plasticizer is investigated using SEM, EDAX analysis and AFM. RPP surface pores with rough surfaces are visible in SEM images, which make them appropriate for plasticizing novel bioplastics with superior mechanical qualities. The plasticizer's heat degradation behaviour is investigated using thermogravimetric and differential thermogram analysis curves. Following the characterization of the synthesised molecules, the plasticization effect was examined using a biodegradable polymer matrix called poly (butylene adipate-co-terephthalate) (PBAT). The reinforcement interface was also examined using scanning electron microscopy analysis. RPP-reinforced films demonstrated greater flexibility and superior surface compatibility at a 5% loading compared to PBAT-only films. Based on a number of reported features, RPP could be a great plasticizer to address future environmental problems.

Evaluating novel biodegradable polymer matrix fertilizers for nitrogen-efficient agriculture.

Enhanced efficiency fertilizers (EEFs) can reduce nitrogen (N) losses in temperate agriculture but are less effective in the tropics. We aimed to design a new EEF and evaluate their performance in simple-to-complex tests with tropical soils and crops. We melt-extruded urea at different loadings into biodegradable polymer matrix composites using biodegradable polyhydroxyalkanoate (PHA) or polybutylene adipate-co-terephthalate (PBAT) polymers with urea distributed throughout the pellet. These contrast with commercially coated EEF that have a polymer-coated urea core. We hypothesized that matrix fertilizers would have an intermediate N release rate compared to fast release from urea or slow release from coated EEF. Nitrogen release rates in water and sand-soil columns confirmed that the matrix fertilizer formulations had a more progressive N release than a coated EEF. A more complex picture emerged from testing sorghum [Sorghum bicolor (L.) Moench] grown to maturity in large soil pots, as the different formulations resulted in minor differences in plant N accumulation and grain production. This confirms the need to consider soil interactions, microbial processes, crop physiology, and phenology for evaluating fertilizer performance. Promisingly, crop δ15N signatures emerged as an integrated measure of efficacy, tracking likely N conversions and losses. The three complementary evaluations combine the advantages of standardized high-throughput screening and more resource-intensive and realistic testing in a plant-soil system. We conclude that melt-blended biodegradable polymer matrix fertilizers show promise as EEF because they can be designed toward more abiotically or more microbially driven N release by selecting biopolymer type and N loading rate.

Tailored release of fluorescence quenched drug from the electrospun nanofiber mat for the treatment of oral submucosal fibrosis (OSMF)

The aim of the presented work involves the preparation and characterization of polycaprolactone (PCL) electrospun nanofibers mats (ESNF) loaded with the drug losartan potassium (LP) as a potential localized treatment strategy for treating OSMF.ESNF mats were fabricated using PCL as the biodegradable polymer matrix within which the drug of choice – LP and super disintegrant (SD) – PVP were mixed. The formed ESNF mats were subjected to thorough physico-chemical characterization.The electrospinning technique resulted in the fabrication of controlled diameter PCL nanofibers with no beading and uniform thickness. The presence of LP or PVP was dispersed uniformly within the polymer matrix and did not result in clump formation. The average diameter of blank PCL was 170 nm and that of LP and PVP loaded was 610 nm.The drug loading and encapsulation efficiency were calculated based on theoretical loading and quantification of the drug after destroying the mats and were found to be 89–92 %. The ex-vivo release profile of LP from PCL ESNF was designed to be tailored to release the drug in a few hours to a few days by the addition of super disintegrants in the polymer matrix. The addition of PVP was able to tune the release of LP from the PCL ESNF mat from 6 days to 17 days when compared to 21 days for samples without PVP. This was further studied using DOE® software that used mathematical software techniques to give the optimized formulation of the LP and PVP-loaded PCL ESNF mat. This optimized formulation was then incorporated in a buccal patch to design an effective system for localized drug delivery application. The optimized buccal patch design was later validated through a mucoadhesive strength study using pig mucosa. The mucoadhesive strength of the buccal patch in pig mucosa showed a force of detachment of 153.30 N/m2 and a force of adhesion of 0.27 N.Hence, a novel PCL-ESNF mat containing LP along with PVP was designed with a tailorable release profile as a possible localized therapeutic platform to alter the overproduction of collagen to provide a cure for OSMF.

Synthesis of ionic liquid modified 1‐D nanomaterial and its strategical distribution into the biodegradable binary polymer matrix to get reduced electrical percolation threshold and electromagnetic interference shielding effectiveness

AbstractIonic liquid is increasingly being used as a chemical modulator of multi‐walled carbon nanotubes (MWCNT). Here, we report the practical method for producing biodegradable electromagnetic interference (EMI) shield films made of thermoplastic polyurethane (TPU), polybutylene adipate‐co‐terephthalate (PBAT), and 1‐(2‐aminoethyl)‐3‐methyl‐1H‐imidazol‐3‐ium modified MWCNT (MIL). The field emission scanning electron microscopy study of cryo‐fractured 50:50 PBAT/TPU blend giving co‐continuous morphology and subsequent polymer EMI shield nanocomposite material had shown the co‐continuous nanofiller distribution. The nanoparticles were chosen to be distributed in the PBAT portion, according to subsequent research employing HRTEM and DMA. The electrical percolation threshold (EPT) is determined to be situated within 1–3 wt% of nanoparticles loading as the remarkable shift in total EMI shielding efficiency from −14.6 dB (for 1 wt%) to −28.6 dB (for 3 wt%) of nanoparticle‐loaded film at 10 GHz (in X‐band region) for a 0.8 mm thick film reveals that the EPT is approximately at 2 wt% of nanoparticle loading. The effective EMI shielding of −37.3 dB was achieved by 10 wt% of MIL loading.

Oxygen vacancy boosting Fenton reaction in bone scaffold towards fighting bacterial infection

Bacterial infection is a major issue after artificial bone transplantation due to the absence of antibacterial function of bone scaffold, which seriously causes the transplant failure and even amputation in severe cases. In this study, oxygen vacancy (OV) defects Fe-doped TiO2 (OV-FeTiO2) nanoparticles were synthesized by nano TiO2 and Fe3O4 via high-energy ball milling, which was then incorporated into polycaprolactone/polyglycolic acid (PCLGA) biodegradable polymer matrix to construct composite bone scaffold with good antibacterial activities by selective laser sintering. The results indicated that OV defects were introduced into the core/shell-structured OV-FeTiO2 nanoparticles through multiple welding and breaking during the high-energy ball milling, which facilitated the adsorption of hydrogen peroxide (H2O2) in the bacterial infection microenvironment at the bone transplant site. The accumulated H2O2 could amplify the Fenton reaction efficiency to induce more hydroxyl radicals (·OH), thereby resulting in more bacterial deaths through ·OH-mediated oxidative damage. This antibacterial strategy had more effective broad-spectrum antibacterial properties against Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). In addition, the PCLGA/OV-FeTiO2 scaffold possessed mechanical properties that match those of human cancellous bone and good biocompatibility including cell attachment, proliferation and osteogenic differentiation.

Gel Polymer Electrolytes with Talc as a Natural Mineral Filler and a Biodegradable Polymer Matrix in Sodium-Ion Batteries.

A gel polymer electrolyte based on poly(vinyl alcohol) (PVA) is used in sodium-ion batteries (SIBs). The use of biodegradable and water-soluble polymer potentially reduces the negative environmental impact. The other components include sodium salt (NaPF6 ), sulfolane (TMS) as a plasticizer and talc. For the first time, natural and abundant talc has been used as an inert filler in a gel polymer electrolyte. The best results were obtained for moderate amounts of filler (1 and 3 wt%). Then, an increase in the conductivity, transference numbers, and thermal stability of the membranes was observed. Moreover, the presence of talc had a positive effect on the cyclability of the hard carbon electrode. The discharge capacity after 50 cycles of HC|1 % T_TMS|Na and HC|3 % T_TMS|Na was 243 and 225 mAh g-1 , respectively. The use of talc in gel polymer electrolytes containing sodium ions improves the safety and efficiency of SIBs.

Boosting the optical properties of polylactic acid/ lanthanide-based metal-organic framework composites

Luminescent lanthanide metal-organic frameworks (LnMOF) are gathering much interest in the scientific community due to their exceptional optical properties, which have the potential to revolutionize several application fields, including anti-counterfeiting. The traceability of the original products is an ever-growing demand for producers and end-users to verify the authenticity of produced goods. Following this newfound need, we propose an anti-counterfeiting method based on a quick-response (QR) code, with a very specific verification procedure, using a luminescent LnMOF-based composite. The embedded code will only react to certain stimulation, hence it can only be unlocked using the sequence that is programmed to respond to. For that purpose, we explored the incorporation of fresh LnMOFs, with europium (EuMOF) and terbium (TbMOF), on a biodegradable polymer matrix of polylactic acid (PLA). A homogeneous mixture of PLA/LnMOF was produced via a two-step process including solvent casting followed by thermal mixing, after achieving the optimized concentration for each filler. The optical characterization of the fresh composites showed an excellent response to selective excitation, with well-defined intraionic lines for TbMOF @ 542 nm (5D4→7F5) and for EuMOF @ 615 nm (5D0→7F2). PLA/Eu, TbMOF composites were also explored to create an additional level of encryption by tuning the emitted color with the appropriate excitation stimuli. Hence, these new luminescent composite materials can be used as traceable optical tags for a wide variety of polymeric products, capable to respond to a very specific excitation wavelength and act as a level three luminescent security marker, whose decoding demands the assessment of more than one factor, with near-impossible replication. Additionally, this technology has a high potential for scalability since the applied processing techniques used for the production of the optically active QR code are commonly employed in the polymer industry. Nevertheless, the analysis of the aged effects clearly indicates the need for a definition of new strategies to enhance the efficiency of the sensitization process of the Ln3+ intraionic emission.

Enhancement of critical-sized bone defect regeneration by magnesium oxide-reinforced 3D scaffold with improved osteogenic and angiogenic properties

• 3D bio-nanocomposite scaffold which have an ideal magnesium ionic microenvironment was developed for critical-sized bony tissue repairing. • Significantly enhanced osteogenic effects were observed over the bio-nanocomposite as compare to the polycaprolactone control. • The rodent femoral and critical-sized cranial defect models were applied to characterize the osteogenesis in vivo . • Magnesium enriched scaffold exhibited remarkably increased bone volume, enhanced angiogenesis, and almost recovered critical-sized defect after an 8-week implantation. The healing of critical-sized bone defects (CSD) remains a challenge in orthopaedic medicine. In recent years, scaffolds with sophisticated microstructures fabricated by the emerging three-dimensional (3D) printing technology have lighted up the treatment of the CSD due to the elaborate microenvironments and support they may build. Here, we established a magnesium oxide-reinforced 3D-printed biocomposite scaffold to investigate the effect of magnesium-enriched 3D microenvironment on CSD repairing. The composite was prepared using a biodegradable polymer matrix, polycaprolactone (PCL), and the dispersion phase, magnesium oxide (MgO). With the appropriate surface treatment by saline coupling agent, the MgO dispersed homogeneously in the polymer matrix, leading to enhanced mechanical performance and steady release of magnesium ion (Mg 2+ ) for superior cytocompatibility, higher cell viability, advanced osteogenic differentiation, and cell mineralization capabilities in comparison with the pure PCL. The in-vivo femoral implantation and critical-sized cranial bone defect studies demonstrated the importance of the 3D magnesium microenvironment, as a scaffold that released appropriate Mg 2+ exhibited remarkably increased bone volume, enhanced angiogenesis, and almost recovered CSD after 8-week implantation. Overall, this study suggests that the magnesium-enriched 3D scaffold is a potential candidate for the treatment of CSD in a cell-free therapeutic approach.

Characterization and Preliminary In Vitro Antioxidant Activity of a New Multidrug Formulation Based on the Co-Encapsulation of Rutin and the α-Acylamino-β-Lactone NAAA Inhibitor URB894 within PLGA Nanoparticles.

A biodegradable and biocompatible polymeric matrix made up of poly(d,l-lactide-co-glycolide) (PLGA) was used for the simultaneous delivery of rutin and the (S)-N-(2-oxo-3-oxetanyl)biphenyl-4-carboxamide derivative (URB894). The goal was to exploit the well-known radical scavenging properties of rutin and the antioxidant features recently reported for the molecules belonging to the class of N-acylethanolamine-hydrolyzing acid amidase (NAAA) inhibitors, such as URB894. The use of the compounds, both as single agents or in association promoted the development of negatively-charged nanosystems characterized by a narrow size distribution and an average diameter of ~200 nm when 0.2-0.6 mg/mL of rutin or URB894 were used. The obtained multidrug carriers evidenced an entrapment efficiency of ~50% and 40% when 0.4 and 0.6 mg/mL of rutin and URB894 were associated during the sample preparation, respectively. The multidrug formulation evidenced an improved in vitro dose-dependent protective effect against H2O2-related oxidative stress with respect to that of the nanosystems containing the active compounds as a single agent, confirming the rationale of using the co-encapsulation approach to obtain a novel antioxidant nanomedicine.

Dielectric Application of Agro-waste Reinforced Polymer Composites: A Review

Proper disposal of agricultural waste and polymers after use has long been one of the toughest environmental problems. Since it solves the majority of environmental issues, this has resulted in the development of commercial materials made from biodegradable and renewable sources, a focus of research around the globe. To make composites that are recyclable and degradable, natural fibres have been developed as reinforcing materials. Composite technology is a successful method to enhance the performance of insulating materials used in power system applications as part of the endeavour to optimize materials for industrial applications. The trend in the development of dielectric materials from agricultural waste (agro-waste) reinforced polymeric composites for use in electrical and electronic power systems is the main focus of this study. This article's objective is to provide a brief overview of the many kinds, best practices, and most often used biodegradable polymer matrix reinforcements in eco-composites for dielectric applications. Dielectric constants, dielectric loss factor, volume resistivity, and other properties of composites made with agro-waste as filler, at various frequencies and filler contents, with and without chemical modifications, have been discussed, as well as their prevails and prospects for the future.

Surface Enhancement of Magnesium Implants for Long Term Applications

Mg is a biodegradable metal that possesses excellent biocompatibility, bioactivity, nontoxic degradation products, and unique mechanical properties. These characteristics make it an attractive element to be used as implant material in physiological environments because it biodegrades and has excellent biocompatibility and bioactivity. In addition, an excess of magnesium ions does not result in cellular toxicity in the human body, where it is often getting rid along with urine. The most significant disadvantage of magnesium is its uncontrolled quick corrosion rate, which can cause rapid loss in mechanical qualities. As a consequence, this might cause the implant to fail before the tissue has completely healed.The purpose of this research is to improve the surface features of the implant, as well as to control the rate at which magnesium corrodes and, as a result, the concentration of magnesium ions that are released into the surrounding environment. This will be accomplished by coating the implant surface with a composite biodegradable polymer (Polycaprolactone PCL) matrix reinforced with MgO Nano-particles which will act as a protective layer to increase the corrosion resistance of magnesium implants. In addition, a laser surface modification procedure was implemented in order to improve the surface's qualities and make certain that there is a strong adhesion between the coating and the surface of the substrate. In order to increase the surface roughness of the specimen, (Nd: YAG) laser device was utilized to create pulses on the surface of the specimen.

Targeted thrombolysis by magnetoacoustic particles in photothrombotic stroke model

BackgroundRecombinant tissue plasminogen activator (rtPA) has a short half-life, and additional hemorrhagic transformation (HT) can occur when treatment is delayed. Here, we report the design and thrombolytic performance of 3 upmum discoidal polymeric particles loaded with rtPA and superparamagnetic iron oxide nanoparticles (SPIONs), referred to as rmDPPs, to address the HT issues of rtPA.MethodsThe rmDPPs consisted of a biodegradable polymeric matrix, rtPA, and SPIONs and were synthesized via a top-down fabrication.ResultsThe rmDPPs could be concentrated at the target site with magnetic attraction, and then the rtPA could be released under acoustic stimulus. Therefore, we named that the particles had magnetoacoustic properties. For the in vitro blood clot lysis, the rmDPPs with magnetoacoustic stimuli could not enhance the lytic potential compared to the rmDPPs without stimulation. Furthermore, although the reduction of the infarcts in vivo was observed along with the magnetoacoustic stimuli in the rmDPPs, more enhancement was not achieved in comparison with the rtPA. A notable advantage of rmDPPs was shown in delayed administration of rmDPPs at poststroke. The late treatment of rmDPPs with magnetoacoustic stimuli could reduce the infarcts and lead to no additional HT issues, while rtPA alone could not show any favorable prognosis.ConclusionThe rmDPPs may be advantageous in delayed treatment of thrombotic patients.

8. Controlling the rate of presentation of BMP-2 from a highly structured composite for interbody fusion

<h3>BACKGROUND CONTEXT</h3> Clinical outcomes for patients with intervertebral disc injury or disease could be enhanced by a new generation of regenerative matrices that create tissue environments to control angiogenesis, chondrogenesis and bone formation. Regenerative matrices are a new class of controlled release biomaterials that use surface chemistry, materials architecture, and drug delivery kinetics to create optimised conditions for cell interactions that result in high quality tissue formation. A novel biodegradable polymer matrix that releases bone morphogenetic protein 2 (BMP-2) over a period of one month with a low Cmax and sustained presentation of active protein is investigated in this study. <h3>PURPOSE</h3> BMP-2 release kinetics and protein activity from a new regenerative matrix was quantified to develop an implant with 1-month release of the drug within a macroporous matrix. A rabbit posterolateral (PLF) vertebral fusion model was performed to assess bone formation and fusion outcomes as a function of dose and source of BMP-2 (E coli and CHO cells). <h3>STUDY DESIGN/SETTING</h3> The study was designed to investigate the effect of various biomaterial design factors and manufacturing methods on the rate of release of BMP-2, the activity of BMP-2 and the extent of in vivo bone formation. <h3>PATIENT SAMPLE</h3> This study did not involve patients. <h3>OUTCOME MEASURES</h3> Outcome measures were the mechanical properties of the regenerative matrix, the architecture and porosity of the matrix, BMP-2 release kinetics, BMP-2 activity as a function of release time and bone formation. <h3>METHODS</h3> BMP-2 activity was tested using two in vitro cell-based assays. BMP-2 solutions and regenerative matrix extracts were tested for their ability to induce alkaline phosphatase (ALP) activity in W-20-17 stromal cells using a modified version of the ASTM standard protocol for in vitro biological activity of recombinant human BMP-2 (F2131-02). Cells were exposed to serial dilutions of BMP-2 for 24 h, assayed for ALP activity and EC50s calculated allowing the relative potency to NIBSC WHO BMP-2 standard to be calculated. BMP-2 release was assessed with an in vitro assay of ALP activity in the mouse muscle myoblast cell line C2C12. Formulations were suspended above a C2C12 monolayer in an insert with a porous (8 µm) PET membrane. Following 3-4 days of exposure, the inserts containing LDGraft were transferred to fresh cells for a further 3-4 days. Cells exposed to LDGraft in this manner were assayed for ALP activity (normalised to protein content) once the inserts had been transferred to fresh cells. Fusion rate and new bone formation were compared to INFUSE in a single-level lumbar (L4-L5) posterolateral (PLF) vertebral fusion model in the New Zealand White rabbit based on standard protocols (Boden et al, 1995, ASTM F3207). Pre-formed implants (3 cc) of INFUSE (rhBMP-2 and absorbable collagen sponge) were implanted on decorticated dorsal surfaces of the transverse processes of L4 and L5 adjacent to the laminae. Fusion was assessed by radiograph at 6 weeks and by manual palpation, radiography and microCT at 12 weeks. <h3>RESULTS</h3> BMP-2 activity was retained over one month of release with the addition of protectants in the formulation and precise control of manufacturing processes. The matrix had a porosity of >70% with a high proportion of macropores (>200 micron diameter). Low doses of E. coli-produced BMP-2 induced fusion in the PLF model. <h3>CONCLUSIONS</h3> A one-month releasing BMP-2 formulation is described. This new regenerative matrix had internal architecture designed to host angiogenesis. Manufacturing and design challenges can be overcome to retain high biologic activity throughout the release period. <h3>FDA DEVICE/DRUG STATUS</h3> BMP-2, not approved for this indication.

Colorimetric indicators of açaí anthocyanin extract in the biodegradable polymer matrix to indicate fresh shrimp

Colorimetric indicator or freshness indicators hold great potential to reduce food waste. Films off açaí anthocyanins extract (AE) with different concentrations molars of two plasticizers glycerol (GLY) or triethyl citrate (TEC), for application fresh shrimp, real time were evaluated. The AE undergoes a visible pink/violet to green/yellowish color change in response to different pH's, which is an indicator of microbial spoilage in shrimp. The CI were exposed to ammonia, and analyzed through infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), ultraviolet spectroscopy, and visual colorimetric. The immobilization of the plasticizers into the CA polymer matrices were confirmed through FT-IR spectra and SEM micrographs. In vitro chromatic transition of the indicators exposed to ammonia vapors, were visually more perceptible when they were produced with 7.2 mols of GLY or 1.8, 3.6, and 7.2 mols of TEC. For the real-time analysis of the application of colorimetric indicators in gray shrimp samples, the indicators that had plasticizers showed perfect color change at the exact time of food deterioration. The colorimetric indicators developed in this study using different molar concentrations of plasticizers are simple, effective and a great eco-friendly alternative to chemical sensors already developed so far.

Comparison between Synthetic and Biodegradable Polymer Matrices on the Development of Quartzite Waste-Based Artificial Stone

The development of artificial stone from the agglutination of polymeric resin using industrial wastes can be a viable alternative from a technical, economic, and sustainable point of view. The main objective of the present work was to evaluate the physical, mechanical, and structural properties of artificial stones based on quartzite waste added into a synthetic, epoxy, or biodegradable polyurethane polymer matrix. Artificial stone plates were produced through the vacuum vibration and compression method, using 85 wt% of quartzite waste. The material was manufactured under the following conditions: 3 MPa compaction pressure and 90 and 80 °C curing temperature. The samples were characterized to evaluate physical and mechanical parameters and microstructure properties. As a result, the artificial stone plates developed obtained ≤0.16% water absorption, ≤0.38% porosity, and 26.96 and 10.7 MPa flexural strength (epoxy and polyurethane resin, respectively). A wear test established both artificial quartzite stone with epoxy resin (AS-EP) and vegetable polyurethane resin (AS-PU) high traffic materials. Hard body impact resistance classified AS-EP as a low height material and AS-PU as a very high height material. The petrographic slides analysis revealed that AS-EP has the best load distribution. We concluded the feasibility of manufacturing artificial stone, which would minimize the environmental impacts that would be caused by this waste disposal. We concluded that the production of artificial rock shows the potential and that it also helps to reduce environmental impacts.

Current Advances in the Roles of Doped Bioactive Metal in Biodegradable Polymer Composite Scaffolds for Bone Repair: A Mini Review

The election of bone tissue engineering scaffolds material is mainly based on the bionics of natural bones. Although the content of trace elements in bone is low, the lack of them affects the growth and metabolism of bones, thus increasing the risk of orthopedic diseases caused by the deterioration of bone quality. Therefore, inspired by trace elements in natural bone, biodegradable polymer composite scaffolds doped with bioactive metals such as Mg, Zn, Sr, Fe, Cu, Mn, Co, Li, Ag, Nb, and V have attracted more attention. Herein, the role of bioactive metals doping in biodegradable polymer matrix is mainly reviewed, including improving hydrophilicity, preventing aseptic inflammation caused by acidic degradation products, imparting antibacterial activity, improving mechanical properties, and promoting vascularization of polymer scaffolds. Then, the reasons and solutions for interfacial bonding and cytotoxicity caused by doping bioactive metals are focused on.