Synthetic Polymeric Materials Research Articles

Material matters: Degradation products affect regenerating Schwann cells

Devices to treat peripheral nerve injury (PNI) must balance many considerations to effectively guide regenerating nerves across a gap and achieve functional recovery. To enhance efficacy, design features like luminal fillers have been explored extensively. Material choice for PNI devices is also critical, as the determining factor of device mechanics, and degradation rate and has increasingly been found to directly impact biological response. This study investigated the ways in which synthetic polymer materials impact the differentiation state and myelination potential of Schwann cells, peripheral nerve glia. Microporous substrates of polycaprolactone (PCL), poly(lactide-co-glycolide) (PLGA) 85:15, or PLGA 50:50 were chosen, as materials already used in nerve repair devices, representing a wide range of mechanics and degradation profiles. Schwann cells co-cultured with dorsal root ganglion (DRG) neurons on the substrates expressed more mature myelination proteins (MPZ) on PLGA substrates compared to PCL. Changes to myelination and differentiation state of glia were reflected in adhesion proteins expressed by glia, including β-dystroglycan and integrin α6, both laminin binding proteins. Importantly, degradation products of the polymers affected glial expression independently of direct attachment. Fast degrading PLGA 50:50 substrates released measurable amounts of degradation products (lactic acid) within the culture period, which may push Schwann cells towards glycolytic metabolism, decreasing expression of early transcription factors like sox10. This study shows the importance of understanding not only material effects on attachment, but also on cellular metabolism which drives myelination responses.

Hygroscopy as an Indicator of Specific Surface Area in Polymer Materials.

Specific surface area (SSA) is an integral characteristic of the interfacial surface in poly-disperse systems, widely used for the assessment of technological properties in polymer materials and composites. Hygroscopic water content (Wh) is an obligate indicator of dispersed materials prior to any analysis of their chemical composition. This study links both indicators for the purpose of the express assessment of SSA using widely available Wh data, on the example of natural (starch, cellulose) and synthetic (acrylic hydrogels) polymer materials. The standard BET analysis of SSA using water vapor desorption was chosen as a reference method. In contrast to the known empirical correlations, this study is based on the fundamental thermodynamic theory of the disjoining water pressure for the connection of the analyzed quantities. The statistical processing of the results for the new methodology and the standard BET method showed their good compliance in a wide range of SSA from 200 to 900 m2/g. The most important methodological conclusion is the possibility of an accurate physically based calculation of hydrophilic SSA in polymer materials using their Wh data at a known relative humidity in the laboratory.

3D-printed PCL@BG scaffold integrated with SDF-1α-loaded hydrogel for enhancing local treatment of bone defects

BackgroundThe long-term nonunion of bone defects is always a difficult problem in orthopaedics treatment. Artificial bone implants made of polymeric materials are expected to solve this problem due to their suitable degradation rate and good biocompatibility. However, the lack of mechanical strength, low osteogenic induction ability and poor hydrophilicity of these synthetic polymeric materials limit their large-scale clinical application.ResultsIn this study, we used bioactive glass (BG) (20%, W/W) and polycaprolactone (PCL, 80%, W/W) as raw materials to prepare a bone repair scaffold (PCL@BG20) using fused deposition modelling (FDM) three-dimensional (3D) printing technology. Subsequently, stromal cell-derived factor-1α (SDF-1α) chemokines were loaded into the PCL@BG20 scaffold pores with gelatine methacryloyl (GelMA) hydrogel. The experimental results showed that the prepared scaffold had a porous biomimetic structure mimicking that of cancellous bone, and the compressive strength (44.89 ± 3.45 MPa) of the scaffold was similar to that of cancellous bone. Transwell experiments showed that scaffolds loaded with SDF-1α could promote the recruitment of bone marrow stromal cells (BMSCs). In vivo data showed that treatment with scaffolds containing SDF-1α and BG (PCL@BG-GelMA/SDF-1α) had the best effect on bone defect repair compared to the other groups, with a large amount of new bone and mature collagen forming at the bone defect site. No significant organ toxicity or inflammatory reactions were observed in any of the experimental groups.ConclusionsThe results show that this kind of scaffold containing BG and SDF-1α serves the dual functions of recruiting stem cell migration in vivo and promoting bone repair in situ. We envision that this scaffold may become a new strategy for the clinical treatment of bone defects.

Characteristics of Bioplastics with Addition of Beeswax and Glucomannan

Packaging for cheese products usually uses plastic with a polymer base. Plastic is divided into two types: plastic made from synthetic polymer raw materials (difficult to decompose) and plastic made from natural polymer raw materials. The impact of using plastic with synthetic polymer materials, or what is usually called commercial plastic, will cause a buildup of waste and result in environmental pollution, so a solution for packaging using bioplastic is needed. This research was conducted to determine the characteristics of bioplastics with the addition of beeswax and glucomannan. By examining the variables of thickness, water resistance, water vapor permeability, biodegradability, tensile strength, and elongation, we will analyze the characteristics of bioplastics that have been enhanced with beeswax and glucomannan. The results showed that the addition of beeswax and glucomannan had no significant effect (p > 0.05) on thickness, water vapor permeability, biodegradability, tensile strength, and elongation. However, the addition of beeswax and glucomannan had a significant effect (p > 0.05) on water resistance. The addition of beeswax and glucomannan also increased (p <0.05) the results of water resistance and tensile strength while reducing (p <0.05) the results of thickness, water vapor permeability, biodegradability, and bioplastic elongation. It can be concluded that beeswax and glucomannan are able to provide strong bioplastic characteristics and have protective properties for products with a longer shelf life at room temperature.

Synthetic polymer materials and their potential applications in treating battlefield injuries

Synthetic polymer materials and their potential applications in treating battlefield injuries

Recent advances in injectable hydrogel therapies for periodontitis.

Periodontitis is an immune-inflammatory disease caused by dental plaque, and deteriorates the periodontal ligament, causes alveolar bone loss, and may lead to tooth loss. To treat periodontitis, antibacterial and anti-inflammation approaches are required to reduce bone loss. Thus, appropriate drug administration methods are significant. Due to their "syringeability", biocompatibility, and convenience, injectable hydrogels and associated methods have been extensively studied and used for periodontitis therapy. Such hydrogels are made from natural and synthetic polymer materials using physical and/or chemical cross-linking approaches. Interestingly, some injectable hydrogels are stimuli-responsive hydrogels, which respond to the local microenvironment and form hydrogels that release drugs. Therefore, as injectable hydrogels are different and highly varied, we systematically reviewed the periodontal treatment field from three perspectives: raw material sources, cross-linking methods, and stimuli-responsive methods. We then discussed current challenges and opportunities for the translation of hydrogels to clinic, which may guide further injectable hydrogel designs for periodontitis.

Anion Exchange Membrane Functionalized by Phenol-formaldehyde Resins: Ion Exchange Capacity, Electrical Properties, Chemical Stability, Permeability, and All-iron Flow Battery

An anion exchange membrane (AEM) is a type of selectively permeable membrane that facilitates the movement of negatively charged ions while impeding the passage of positively charged ions. These membranes are designed to selectively transport anions across them based on their charge and size. They are commonly used in various electrochemical devices and processes, such as fuel cells, electrodialysis, electrolysis, water treatment, and other applications requiring ion exchange. These membranes are typically made from synthetic polymer materials with positively charged functional groups that attract and transport anions while repelling cations. They are used for selection, conduction, and stabilizing the ion anion exchange phenomena. We recently released a study on the creation of a quick and easy approach to creating an AEM with increased ionic conduction capacity and good alkaline stability. The technique's simplicity makes it a desirable substitute for conventional methods. By using this approach, the carcinogenic reagent often employed for AEM preparation—chloromethyl methyl ether—is avoided. Membrane surfaces appeared to be rather homogeneous in Scanning Electron Microscope (SEM) pictures. Water content, ion exchange capacity, and electrical conductivity all improved as the amount of ion-exchange material in the casting fluid increased. The Thermogravimetric Analysis (TGA) of the membranes revealed thermal stability up to 150°C which shows that these membranes are ideal for applications in that temperature range. The composite membranes exhibited enhanced chemical stability in strong chemical environments and this can be attributed to the resonance stabilized guanidine group as negative ion-exchange site. By considering the AC impedance data, the conductivity measurements showed a marked enhancement in conductivity by increasing the content of ion-exchange material. Galvanostatic charged discharge tests were used to examine the electrochemical performance of an all-iron redox flow cell, and the system demonstrated a columbic efficiency of 80% during the repeated charge-discharge cycles. The findings of this work provide a compelling alternative to the established methods for the synthesis of AEMs.

Analysis of tensile strength of composite fiber reinforced with areca Nut Skin Fiber using BQTN 157 EX Resin

In the development of materials science, especially polymers, natural fibers such as areca nut shell fiber are increasingly attractive to use. The use of synthetic polymer materials made from fiber can replace conventional materials such as metal, wood and leather. They can replace conventional materials with the advantages of lower price, environmental friendliness, and recyclability. Areca nut shell fiber, as an example of a natural fiber, has great potential in the furniture industry, crafts, and as an ingredient in traditional medicine. This fiber is used as a reinforcing material in composites with an Unsaturated Polyester Yukalac resin matrix. Unsaturated Polyester Yukalac resin, with characteristics such as stiffness, flexibility, water resistance, chemical resistance and weather resistance, is used as a matrix in making composites. The aim of this research is to make a plastic composite prototype reinforced with areca palm fiber, varying the volume fraction of areca nut shell fiber by 30%:50%, 50%:60%, 70%:70%, 90%:80% and for the matrix using polyester resin. BQTN 157 EX. The fiber composition is arranged in a mold in the same direction using the hand lay up method. Composite testing is in the form of a tensile test referring to the ASTM 638-03 standard. The results of the largest tensile testing process were with a volume fraction of 50% with an average value of 7.11 MPa, and for tensile testing the lowest was a volume fraction of 70% with an average value of 6.17 MPa, it can be concluded for reinforced plastic composites Areca nut shell fiber has considerable ability to be applied as a structural material. This is a step towards the development of innovative and environmentally friendly composite materials for various industrial applications.

Exploiting Benefits of Vaterite Metastability to Design Degradable Systems for Biomedical Applications.

The widespread application of calcium carbonate is determined by its high availability in nature and simplicity of synthesis in laboratory conditions. Moreover, calcium carbonate possesses highly attractive physicochemical properties that make it suitable for a wide range of biomedical applications. This review provides a conclusive analysis of the results on using the tunable vaterite metastability in the development of biodegradable drug delivery systems and therapeutic vehicles with a controlled and sustained release of the incorporated cargo. This manuscript highlights the nuances of vaterite recrystallization to non-porous calcite, dissolution at acidic pH, biodegradation at in vivo conditions and control over these processes. This review outlines the main benefits of vaterite instability for the controlled liberation of the encapsulated molecules for the development of biodegradable natural and synthetic polymeric materials for biomedical purposes.

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) Bionanocomposites with Crystalline Nanocellulose and Graphene Oxide: Experimental Results and Support Vector Machine Modeling.

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) is a biodegradable and biocompatible bacterial copolymer used in the biomedical and food industries. However, it displays low stiffness and strength for certain applications. This issue can be solved via reinforcement with nanofillers. In this work, PHBHHx-based bionanocomposites reinforced with different loadings of crystalline nanocellulose (CNC) and graphene oxide (GO) were developed by a green and straightforward solution casting technique. Their crystalline nature and surface topography were explored via X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively, their composition was corroborated via Fourier-transformed infrared spectroscopy (FTIR), and their crystallization and melting behavior were determined via differential scanning calorimetry (DSC). The nanofillers had a nucleating role, raising the crystallization temperature of the polymer, whilst hardly any changes were found in the melting temperature. Further, significant enhancements in the stiffness, strength, and thermal stability of the PHBHHx matrix were observed with the incorporation of both nanofillers, which was attributed to a synergic effect. The mechanical properties for various concentrations of CNC and GO were accurately predicted using a machine learning (ML) model in the form of a support vector machine (SVM). The model performance was evaluated in terms of the mean absolute error (MAE), the mean square error (MSE), and the correlation coefficient (R2). These bio-based nanocomposites are a valuable alternative to conventional petroleum-based synthetic polymeric materials used nowadays for biomedicine and food packaging applications.

Robust, Fully Biodegradable Films of Polyesters Realized by In Situ Formation of an Interconnected Multi-Nanolayer Structure under Extensional Flow.

Multilayer structures are not only applied to manipulate properties of synthetic polymer materials such as rainbow films and barrier films but also widely discovered in natural materials like nacre. In this work, in situ formation of an interconnected multi-nanolayer (IMN) structure in poly(butylene adipate-co-terephthalate) (PBAT)/poly(butylene succinate) (PBS) cocontinuous blends is designed by an extensional flow field during a "casting-thermal stretching" process, combining the properties of two components to a large extent. Hierarchical structures including phase morphology, crystal structure, and lamellar crystals in IMN films have been revealed, which clearly identifies the crucial role of extensional flow. The oriented PBAT phase in the IMN structure can be beneficial to the epitaxial growth of PBS crystals onto the PBAT nanolayers, thus improving interfacial adhesions. Furthermore, intense extensional stress can also promote crystallinity and thicken the lamellar structure. Given such distinct features in the fully biodegradable films, a simultaneous enhancement in tear strength, tensile strength, and puncture resistance has been achieved. To the best of our knowledge, the tear strength of IMN films about 285.9 kN/m is the highest level in the previous works of this system. Moreover, the proposed fabrication way of the IMN structure is facile and scalable, which is highly expected to be an efficient strategy for development of structured biodegradable polymers with excellent comprehensive properties.

Investigation of the Physicochemical Interactions and Modification Effects of Polyurethane on Asphalt Binder

Polyurethane (PU) is a synthetic polymeric material with excellent mechanical properties and chemical designability. An in-depth understanding of the synergetic effect between polyurethane and asphalt binder is needed to produce durable PU-modified asphalt paving materials. This study focuses on the physicochemical changes, the states of in situ synthesized PU, and the modification effects of PU after PU prepolymers and chain extenders are added into asphalt binder. Investigation methods involve the Fourier transform infrared (FTIR) spectroscopy, partial Corbett separation, confocal fluorescence microscopy, particle size distribution test, rheological test, and theoretical calculation. It was found that the incorporation of PU has no obvious chemical influence on the asphalt binder and the main working principle of PU modification is its physical dispersion in asphalt binder. In situ synthesized PU is uniformly dispersed in asphalt binder and the size distribution of PU particles follows a log-normal distribution. As PU content exceeds 15%, the formed PU particles in asphalt binder are noticeably enlarged. Moreover, PU modification leads to significant improvements in asphalt binder properties, including high-temperature rutting resistance, elastic recovery, and deformation resistance. Rheological experiments and theoretical calculations under the framework of suspension rheology indicate that PU-modified asphalt binder can be reasonably modeled as a bimodal solid particle suspension, and the dynamic viscosity of PU-modified asphalt binder is predominantly determined by the dynamic viscosity of the maltenes and the volume fractions of PU and asphaltenes.

Preparation of drug-loaded chitosan microspheres repair materials.

With the development of society and the progress of science and technology, microspheres, as a new polymer material, have been applied to all aspects of human beings. Microspheres can play a huge role in food safety, electronic technology, sewage treatment, biomedicine, etc., and are non-toxic or harmless. There are three main types of substrates for the preparation of microspheres: natural polymers, semi-synthetic polymer materials, and synthetic polymer materials. In this study, the inorganic material kaolin was modified by the emulsification-crosslinking method with chitosan and composite microspheres with large interlayer spacing were prepared, which were characterized by Fourier Transform Ioncyclotron Resonancel (FTIR) analysis and Scanning Electron Microscope (SEM). The prepared kaolin/chitosan microspheres were then placed in different amounts of aspirin and the optimal dose was investigated by encapsulation efficiency and drug loading rate. The drug release rate of 0.5 h, 1 h, 1.5 h, 2 h, 4 h, 6 h, and 12 h was then determined by simulating the human colon to determine the performance of the sustained-release drug. The experimental results showed that after the prepared composite microspheres were loaded with aspirin drug, we got the optimal dosage of 0.1 g by discussing the encapsulation efficiency and drug loading rate of the drug-loaded microspheres, and the encapsulation efficiency reached 80.80%, while the drug loading rate was 24.40%, the drug release capacity reached about 83% in about 12 hours. The research shows that the kaolin/chitosan drug-loaded microspheres prepared by the emulsification and cross-linking method are excellent drug-loading materials.

Bioplastics from Kitchen Wastes: A Developing Green Technology

Plastic waste has become one of the biggest problems due to their excessive use. Decomposition of bioplastics is very difficult as a result its causes lot of negative impact to landfill and water pollution. The most possible solution to overcome this problem is to substitute synthetic polymeric materials with biodegradable materials suchas bioplastics. Food wastes can be transformed into environment friendly bioplastics, which will not only reduce environmental pollution due to natural fermentation of these wastes, but also generate National revenue besides generating employment potentials. These polymers can be degraded environmentally by microorganisms and water in compost piles. Application of Bioplastics has several advantages over conventional plastics such as lower carbon footprint and greenhouse gases (GHG) emissions, lower energy cost in manufacturing, reduction of permanent litter, and much safer to the environment. In food Industries, the need for high-standard storage features and the urge for packaging with high economic, low ecological impact, ease of customization, and low encumbrance can be answered by compostable or degradable bioplastics where kitchen waste may take essential role. Advancements in biomedical applications of bioplastics lead to the development of drug delivery systems and therapeutic devices for tissue engineering. Nanocellulose and its composites, which may be obtained from the processing of kitchen wastes, may result in potential and economical sources for green plastic studies about the fabrication of medical implants, either in dental, orthopedic, or biomedical fields.

The clinical effectiveness of staple line reinforcement with different matrix used in surgery.

Staplers are widely used in clinics; however, complications such as bleeding and leakage remain a challenge for surgeons. To tackle this issue, buttress materials are recommended to reinforce the staple line. This Review provides a systematic summary of the characteristics and applications of the buttress materials. First, the physical and chemical properties of synthetic polymer materials and extracellular matrix used for the buttress materials are introduced, as well as their pros and cons in clinical applications. Second, we review the clinical effects of reinforcement mesh in pneumonectomy, sleeve gastrectomy, pancreatectomy, and colorectal resection. Based on the analysis of numerous research data, we believe that buttress materials play a crucial role in increasing staple line strength and reducing the probability of complications, such as bleeding and leakage. However, considering the requirements of bioactivity, degradability, and biosafety, non-crosslinked small intestinal submucosa (SIS) matrix material is the preferred candidate. It has high research and application value, but further studies are required to confirm this. The aim of this Review is to provide comprehensive guidance on the selection of materials for staple line reinforcement.

Fabrication of Sacha Inchi Oil-Loaded Microcapsules Employing Natural-Templated Lycopodium clavatum Spores and Their Pressure-Stimuli Release Behavior.

Polymeric particles have attracted vast attention for use in various fields, especially as drug carriers and cosmetics, due to their excellent ability to protect active ingredients from the environment until reaching a target site. However, these materials are commonly produced from conventional synthetic polymers, which impose adverse effects on the environment due to their non-degradable nature, leading to waste accumulation and pollution in the ecosystem. This work aims to utilize naturally occurring Lycopodium clavatum spores to encapsulate sacha inchi oil (SIO), which contains active compounds with antioxidant activity, by applying a facile passive loading/solvent diffusion-assisted method. Sequential chemical treatments by acetone, potassium hydroxide, and phosphoric acid were employed to remove native biomolecules from the spores before encapsulation effectively. These are mild and facile processes compared to other synthetic polymeric materials. Scanning electron microscopy and Fourier-transform infrared spectroscopy revealed the clean, intact, and ready-to-use microcapsule spores. After the treatments, the structural morphology of the treated spores remained significantly unchanged compared to the untreated counterparts. With an oil/spore ratio of 0.75:1.00 (SIO@spore-0.75), high encapsulation efficiency and capacity loading values of 51.2 and 29.3%, respectively, were obtained. Using antioxidant assay (DPPH), the IC50 of SIO@spore-0.75 was 5.25 ± 3.04 mg/mL, similar to that of pure SIO (5.51 ± 0.31 mg/mL). Under pressure stimuli (1990 N/cm3, equivalent to a gentle press), a high amount of SIO was released (82%) from the microcapsules within 3 min. At an incubation time of 24 h, cytotoxicity tests showed a high cell viability of 88% at the highest concentration of the microcapsules (10 mg/mL), reflecting biocompatibility. The prepared microcapsules have a high potential for cosmetic applications, especially as functional scrub beads in facial washing products.

Molecular Dynamics Investigation of the Pressure Dependence of Glass Formation in a Charged Polymer Melt

Most commodity polymers are derived from petroleum raw materials, and correspondingly, these materials are normally uncharged and nonpolar, attributes that make this class of material relatively insoluble in water and relatively slow to breakdown in the environment. Natural and synthetic charged polymer materials often do not exhibit these drawbacks, thereby offering the potential for being more sustainable. As with all polymer materials, properties related to glass formation play a central role in the design and characterization of materials. Here, we investigate the influence of a crucial processing variable, the pressure P, on the glass formation of a coarse-grained charged polymer melt using molecular dynamics simulation. We find that the temperature (T) dependence of the thermodynamics and segmental dynamics under variable P conditions largely resemble the trends observed before for uncharged polymer liquids. In particular, we are able to organize all our segmental relaxation data as functions of both T and P in terms of the conventional phenomenology for uncharged polymer melts, namely, the Vogel–Fulcher–Tammannn temperature dependence of the structural relaxation time τα and a pressure analog of this equation, etc. Moreover, we can quantitatively describe all our simulation data for both charged and uncharged polymer melts with the string model of glass formation. Importantly, our results indicate that the main effect of charge on the dynamics of polymeric glass-forming liquids is to “renormalize” the cohesive interaction strength. This opens the possibility of applying theories of neutral polymer melts to describe the glass formation of synthetic and natural charged polymer melts, ionic fluids, and possibly even polar polymer melts, once an accounting is made for how charge modifies the effective cohesive interaction strength.

One Stone, Two Birds: Spidroin‐Inspired Nanogels for High‐Performance Fibers and Photothermal Actuators

AbstractThe exciting development of hydrogels makes it a promising candidate to be applied in various fields. However, it remains a great challenge to store the precursors of hydrogels and to process them after gelation, like synthetic polymer materials. Herein, spidroin‐inspired novel nanogels with extraordinary processability, which can be spun into fibers via direct drawing and fabricated into thermal actuators easily after gelation are prepared. These soluble and spinnable nanogels are composed of a liquid metal core and a poly (acrylic acid) (PAA) shell and are entangled with each other. The as fabricated nanogels and diluted dope solution can be stored >1 month. The as‐spun nanogel fibers with hierarchical structures achiev extraordinary mechanical properties (tensile stress of 575 MPa, toughness of 381 MJ m−3) and supercontraction at 60% RH. Besides, a photothermal actuator is prepared by coating the nanogels on a polyethylene substrate with a commercial shading ink, and the as‐prepared actuator shows a rapid response to near‐infrared light as well as a fast recovery. Molecular dynamics simulation reveals a possible working mechanism of the actuator. This study provides a new strategy to prepare processable nanogels with broad application prospects for smart textiles and soft robots.

Potentiality of sustainable corn starch-based biocomposites reinforced with cotton filter waste of spinning mill

The textile sector is among the leading industries globally in terms of releasing pollutants and producing waste. Despite being reusable, many wastes are squandered by disposing to landfills or incineration, creating a serious environmental threat. Because the cost of raw materials makes up a significant portion of the total product cost, manufacturers can obtain significant profits by exploiting waste generated during the manufacturing process. Herein, an attempt has been taken to utilize cotton filter waste (CFW) (collected from the humidification plant of the spinning mill) as reinforcement in manufacturing biocomposites with the corn starch (CS) matrix. Starch was considered to be the most suitable matrix as it is sustainable, abundant, natural, biodegradable, and, more importantly, capable of showing thermoplastic behavior under high temperatures. Sheets of corn starch composites reinforced with different wt% of cleaned cotton filter waste were fabricated using hand layup and compression molding techniques. The 50 wt% cotton waste was found to be optimum loading in terms of tensile strength, Young's modulus, bending strength, toughness, impact strength, and thermal Conductivity of the biocomposites. SEM micrographs revealed good interfacial adhesion (bonding) in matrix and filler interfaces, with the most substantial bonding for composites containing 50% fibers that concomitantly enhanced the mechanical properties of composites. The obtained biocomposites are deemed to be a sustainable alternative to non-degradable synthetic polymeric materials like Styrofoam for packaging and insulation applications.

The histologic reaction and permanence of hyaluronic acid gel, calcium hydroxylapatite microspheres, and extracellular matrix bio gel.

The filling materials on the beauty market can be classified into three types: natural biological materials, synthetic polymer materials, and composites containing bioactive substances. However, comparative experimental data is lacking to compare their biological responses and permanence. The main object of this study was to evaluate the biological response of these three types of fillers to provide a theoretical basis for clinical application. Six-week-old female mice were injected subcutaneously with hyaluronic acid (HA) gel, calcium hydroxylapatite (CaHA) microspheres, and extracellular matrix (ECM) bio gel to observe the body reaction and permanence. At 1, 4, 8, and 16 weeks, the test sites were excised and analyzed by histopathology and proteomics. Extracellular matrix had a minimal foreign body response. HA had a good volume effect at the early stage but the volume retention rate was lower than CaHA in the long term. CaHA could stimulate neo-collagen formation. This study has proven the effectiveness and safety of these fillers and could provide clinical guidance for the plastic surgeon.