Polyhexamethylene guanidine hydrochloride as promising active ingredient for oral antiseptic products to eliminate microorganisms threatening the health of endangered wild cats: a comparative study with chlorhexidine digluconate

The aim of this study was to evaluate the antimicrobial efficacy of polyhexamethylene hydrochloride guanidine (PHMGH) compared to chlorhexidine digluconate (CLX) for use as an oral antiseptic during dental procedures in wild cats. This research is crucial due to limited information on the diversity of oral microorganisms in wild cats and the detrimental local and systemic effects of oral diseases, which highlights the importance of improving prevention and treatment strategies. Samples were collected from the oral cavities of four Puma concolor, one Panthera onca, and one Panthera leo, and the number of colony-forming units per milliliter (CFU/mL) was counted and semi-automatically identified. The antimicrobial susceptibility profile of bacterial isolates was determined using minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and time-kill kinetics of PHMGH and CLX. A total of 16 bacterial isolates were identified, consisting of six Gram-positive and 10 Gram-negative. PHMGH displayed MIC and MBC from 0.24 to 125.00 μg/mL, lower than those of CLX against three isolates. Time-kill kinetics showed that PHMGH reduced the microbial load by over 90% for all microorganisms within 30 min, whereas CLX did not. Only two Gram-positive isolates exposed to the polymer showed incomplete elimination after 60 min of contact. The results could aid in the development of effective prevention and treatment strategies for oral diseases in large felids. PHMGH showed promising potential at low concentrations and short contact times compared to the commercial product CLX, making it a possible active ingredient in oral antiseptic products for veterinary use in the future.

A niche-mimicking polymer hydrogel-based approach to identify molecular targets for tackling human pancreatic cancer stem cells

BACKGROUND

Pancreatic adenocarcinoma (PAAD) is one of the most fatal human cancers, but effective therapies remain to be established. Cancer stem cells (CSCs) are highly resistant to anti-cancer drugs and a deeper understanding of their microenvironmental niche has been considered important to provide understanding and solutions to cancer eradication. However, as the CSC niche is composed of a wide variety of biological and physicochemical factors, the development of multidisciplinary tools that recapitulate their complex features is indispensable. Synthetic polymers have been studied as attractive biomaterials due to their tunable biofunctionalities, while hydrogelation technique further renders upon them a diversity of physical properties, making them an attractive tool for analysis of the CSC niche.

METHODS

To develop innovative materials that recapitulate the CSC niche in pancreatic cancers, we performed polymer microarray analysis to identify niche-mimicking scaffolds that preferentially supported the growth of CSCs. The niche-mimicking activity of the identified polymers was further optimized by polyethylene glycol (PEG)-based hydrogelation. To reveal the biological mechanisms behind the activity of the optimized hydrogels towards CSCs, proteins binding onto the hydrogel were analyzed by liquid chromatography with tandem mass spectrometry (LC-MS/MS), and the potential therapeutic targets were validated by looking at gene expression and patients' outcome in the TCGA database.

RESULTS

PA531, a heteropolymer composed of 2-methoxyethyl methacrylate (MEMA) and 2-(diethylamino)ethyl methacrylate (DEAEMA) (5.5:4.5) that specifically supports the growth and maintenance of CSCs was identified by polymer microarray screening using the human PAAD cell line KLM1. The polymer PA531 was converted into five hydrogels (PA531-HG1 to HG5) and developed to give an optimized scaffold with the highest CSC niche-mimicking activities. From this polymer that recapitulated CSC binding and control, the proteins fetuin-B and angiotensinogen were identified as candidate target molecules with clinical significance due to the correlation between gene expression levels and prognosis in PAAD patients and the proteins associated with the niche-mimicking polymer.

CONCLUSION

This study screened for biofunctional polymers suitable for recapitulation of the pancreatic CSC niche and one hydrogel with high niche-mimicking abilities was successfully fabricated. Two soluble factors with clinical significance were identified as potential candidates for biomarkers and therapeutic targets in pancreatic cancers. Such a biomaterial-based approach could be a new platform in drug discovery and therapy development against CSCs, via targeting of their niche.

Progress of tissue adhesives based on proteins and synthetic polymers

In recent years, polymer-based tissue adhesives (TAs) have been developed as an alternative to sutures to close and seal incisions or wounds owing to their ease of use, rapid application time, low cost, and minimal tissue damage. Although significant research is being conducted to develop new TAs with improved performances using different strategies, the applications of TAs are limited by several factors, such as weak adhesion strength and poor mechanical properties. Therefore, the next-generation advanced TAs with biomimetic and multifunctional properties should be developed. Herein, we review the requirements, adhesive performances, characteristics, adhesive mechanisms, applications, commercial products, and advantages and disadvantages of proteins- and synthetic polymer-based TAs. Furthermore, future perspectives in the field of TA-based research have been discussed.

Zirconium/lanthanum-modified chitosan/polyvinyl alcohol composite adsorbent for rapid removal of fluoride

A novel and easily separable adsorbent in the shape of a membrane for the rapid removal of fluoride from water was prepared after testing Zr, La and LaZr to modify a chitosan/polyvinyl alcohol composite adsorbent (CS/PVA-Zr, CS/PVA-La, CS/PVA-LA-Zr). The CS/PVA-La-Zr composite adsorbent can remove a large amount of fluoride within 1 min of contact time, and the adsorption equilibrium can be reached within 15 min. The fluoride adsorption behavior of the CS/PVA-La-Zr composite can be described by pseudo-second-order kinetics and Langmuir isotherms models. The morphology and structure of the adsorbents were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The adsorption mechanism was studied using Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), and which showed that ion exchange occurred mainly with hydroxide and fluoride ions. This study showed that an easily operable, low-cost and environmentally friendly CS/PVA-La-Zr has the potential to remove fluoride effectively from drinking water in a short time.

Grafting of proteins onto polymeric surfaces: A synthesis and characterization challenge

This review aims at answering the following question: how can a researcher be sure to succeed in grafting a protein onto a polymer surface? Even if protein immobilization on solid supports has been used industrially for a long time, hence enabling natural enzymes to serve as a powerful tool, emergence of new supports such as polymeric surfaces for the development of so-called intelligent materials requires new approaches. In this review, we introduce the challenges in grafting protein on synthetic polymers, mainly because compared to hard surfaces, polymers may be sensitive to various aqueous media, depending on the pH or reductive molecules, or may exhibit state transitions with temperature. Then, the specificity of grafting on synthetic polymers due to difference of chemical functions availability or difference of physical properties are summarized. We present next the various available routes to covalently bond the protein onto the polymeric substrates considering the functional groups coming from the monomers used during polymerization reaction or post-modification of the surfaces. We also focus our review on a major concern of grafting protein, which is avoiding the potential loss of function of the immobilized protein. Meanwhile, this review considers the different methods of characterization used to determine the grafting efficiency but also the behavior of enzymes once grafted. We finally dedicate the last part of this review to industrial application and future prospective, considering the sustainable processes based on green chemistry.

Biodegradability of polyethylene by efficient bacteria from the guts of plastic-eating waxworms and investigation of its degradation mechanism

Polyethylene (PE) has been regarded as non-biodegradable for decades, and the evidence for its degradation by bacteria remains unclear in the literature. Waxworms have recently gained attention for their ability to degrade natural long-chain polymers and synthetic plastic. This study aims to explore the potential of low-density polyethylene (LDPE)-degrading bacteria from the gut symbionts of lesser waxworm (Achroia grisella) larvae for the effective biodegradation of LEDP. Two bacterial isolates (LDPE-DB1 and LDPE-DB2) exhibited the greatest reduction in tensile strength among all isolates (P < 0.0001), reaching 51.3% and 58.3%, respectively. The bacterial strains LDPE-DB1 and LDPE-DB2 stand for molecularly identified species, Citrobacter freundii and Bacillus sp., respectively. After 5 days of incubation, the cell density of LDPE-DB1 and LDPE-DB2 reached 2.20 × 10⁸ and 1.8 × 10⁸ CFU/mL, respectively. However, after 30 days of incubation, the cell density reached 7.3 × 10⁸ and 5.9 × 10⁸, respectively. The formed cavities indicate the high activity of the isolated bacteria from Achroia grisella larvae where the cavities reach a depth of up to 1.2 µm. The findings of this study demonstrated the presence of LDPE-degrading bacteria in Achroia grisella and provide promising evidence for the biodegradation of plastic waste management in the environment.

Microplastics, both non-biodegradable and biodegradable, do not affect the whole organism functioning of a marine mussel

Microplastics are ubiquitous in the marine environment, and their uptake by many organisms has been well documented. Concern about increasing plastic waste in ecosystems and organisms has led to the production of biodegradable alternatives. However, long breakdown times of biodegradable plastics in natural environments mean they still have the potential to induce ecological impacts. The impacts of microplastics on organisms remain unclear, especially as many experimental microplastic exposures employ particle concentrations orders of magnitude greater than those found in natural ecosystems. Here, we exposed the ecosystem engineer, the Asian green mussel Perna viridis, to non-biodegradable and biodegradable microplastics at two environmentally relevant concentrations (~17-20 particles L^-1 and ~ 135-140 particles L^-1). After four weeks of exposure, there were no significant effects of microplastic type or concentration on the mortality, oxygen consumption rate, clearance rate, or condition index of P. viridis. With the increasing body of microplastic literature, future exposure studies considering biotic effects should make efforts to employ environmentally relevant concentrations. Further, we suggest that, while a high-profile threat to ecosystems, investigating the effects of microplastics on ecosystems should be conducted alongside, and not draw focus away from, other major threats such as climate change.

From carrion-eaters to plastic material plunderers: Toxicological impacts of plastic ingestion on black vultures, Coragyps atratus (Cathartiformes: Cathartidae)

Despite plastic ingestion has already been reported in several bird species, its physiological impacts have been little inspected, especially in representatives of the Cathartidae family. Thus, in this study, we aimed to identify, characterize, and evaluate the effects arising from the ingestion of plastic materials by Coragyps atratus adults, that captured in landfill areas. Herein, a total of 51 individuals were captured, the frequency of plastic intake being higher than 40%. The plastic materials consisted mainly of low-density polyethylene and film-type polystyrene, as well as presenting irregular shapes and diameters between 10 and 30 mm. Biochemically, we observed in animals that contained plastics in the stomach ("plastic" group) high production of reactive oxygen species (ROS), hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) - especially in the intestine, muscle and brain - whose activity of catalase (CAT) and superoxide dismutase (SOD) was not sufficient to counteract the oxidative stress. Moreover, in the liver of these same animals, we observed high production of nitrite and nitrate, suggesting a hepatic nitrosative stress. Plus, we observed a cholinesterase effect in animals from the "plastic" group, marked by increased activity of butyrylcholinesterase (BChE) (in the brain) and muscle and cerebral acetylcholinesterase (AChE). On the other hand, the biochemical changes perceived were not significantly correlated with the identified plastic material concentrations (2.808 ± 0.598 items/g of stomach content and 0.276 ± 0.070 items/g of stomach - fresh weight), body condition of the animals, size, and shape of the identified plastic materials. Hence, our study sheds the light on the toxicity of plastics deposited in landfills and their ingestion by C. atratus, which reinforces the hypothesis that these materials are harming the health of these birds and, consequently, the dynamics of their populations.

Microplastic contamination and characteristics spatially vary in the southern Black Sea beach sediment and sea surface water

In this study, the abundance, and characteristics of the microplastics on the southern coast of the Black Sea were assessed. More than 70% of the detected microplastics were smaller than 2.5 mm and mostly consisted of fibers and fragments. The average microplastic abundance in the beach sediment and seawater were 64.06 ± 8.95 particles/kg and 18.68 ± 3.01 particles/m³, respectively. The western coast of the study area (Marmara region) was the most polluted area, and a spatially significant difference was determined in terms of abundance. The composition in the beach sediment (particles/kg) was dominated by styrene acrylonitrile copolymer (SAC) (40.53%), polyethylene terephthalate (PET) (38.75%), and polyethylene (PE) (6.91%), whereas the seawater (particles/m³) was dominated by PET (57.26%), PE (13.52%), and polypropylene PP (11.24%). The results of our study can be a baseline for environmental modeling studies and experimental studies on the marine organisms inhabiting the Black Sea.

A novel nano-hydroxyapatite/synthetic polymer/bone morphogenetic protein-2 composite for efficient bone regeneration

BACKGROUND

Efficient bone regeneration using recombinant human bone morphogenetic protein-2 (BMP-2) is needed to reduce side effects caused by high-dose BMP-2 use. The composite material of polylactic acid-polyethene glycol (PLA-PEG) for sustained release and an osteogenic nano-hydroxyapatite (nHAp) can contribute to efficient bone regeneration by BMP-2.

STUDY DESIGN

An experimental in vitro and in vivo study.

PURPOSE

The objective of this study is to investigate the effectiveness of a novel composite material of PLA-PEG and nHAp as a carrier for BMP-2.

METHODS

The release kinetics of BMP-2 from the composites was investigated by ELISA. Thirty-six male Sprague-Dawley rats underwent posterolateral spinal fusion on L4-L5 with three different doses of BMP-2 (0 µg [control], 3 µg [low dose], and 10 µg [high dose]). Weekly µCT results and histology and a manual palpation test at 8 weeks postoperatively were used for assessment of the spinal fusion.

RESULTS

ELISA demonstrated the sustained release of BMP-2 until day 21. µCT and manual palpation test demonstrated a solid fusion in 91.6% (11/12) of specimens in both the low- and high-dose groups. N mice in the control group attained bony fusion (0%, 0/9). nHAp was resorbed between 2 and 4 weeks postoperatively, and regenerated fusion mass at 8 weeks postoperatively consisted of only newly formed bone.

CONCLUSIONS

The nHAp/PLA-PEG composite enabled efficient bone regeneration with low-dose BMP-2. The sustained release of BMP-2 by PLA-PEG and the osteogenic and biodegradable scaffold of nHAp might contribute to efficient bone regeneration.

CLINICAL SIGNIFICANCE

This novel composite material has potential in clinical applications (spinal fusion, large bone defect and non-union) by enabling efficient bone formation by BMP-2.

Biomaterials and strategies for repairing spinal cord lesions

Spinal cord injury (SCI) causes intractable disease and leads to inevitable physical, financial, and psychological burdens on patients and their families. SCI is commonly divided into primary and secondary injury. Primary injury occurs upon direct impact to the spinal cord, which leads to cell necrosis, axon disruption, and vascular loss. This triggers pathophysiological secondary injury, which has several phases: acute, subacute, intermediate, and chronic. These phases are dependent on post-injury time and pathophysiology and have various causes, such as the infiltration of inflammatory cells and release of cytokines that can act as a barrier to neural regeneration. Another unique feature of SCI is the glial scar produced from the reactive proliferation of astrocytes, which acts as a barrier to axonal regeneration. Interdisciplinary research is investigating the use of biomaterials and tissue-engineered fabrication to overcome SCI. In this review, we discuss representative biomaterials, including natural and synthetic polymers and nanomaterials. In addition, we describe several strategies to repair spinal cord injuries, such as fabrication and the delivery of therapeutic biocomponents. These biomaterials and strategies may offer beneficial information to enhance the repair of spinal cord lesions.

Critical evaluation of biodegradation studies on synthetic plastics through a systematic literature review

Increasing amounts of plastic waste in the environment and their fragmentation into smaller particles known as microplastics (particles, <5mm) have raised global concerns due to their persistency in the environment and their potential to act as vectors for harmful substances or pathogenic microorganisms. One possible solution to this problem is biodegradation of plastics by microorganisms. However, the scientific information on plastic-degrading microorganisms is scattered across different scientific publications. We conducted a systematic literature review (SLR) with predefined criteria using the online databases of Scopus and Web of Science to find papers on bacterial biodegradation of synthetic petroleum-based polymers. The aims of this SLR were to provide an updated list of all of the currently known bacteria claimed to biodegrade synthetic plastics, to determine and define the best methods to assess biodegradation, to critically evaluate the existing studies, and to propose directions for future research on polymer biodegradation in support of more rapid development of biodegradation technologies. Most of the bacteria identified here from the 145 reviewed papers belong to the phyla Proteobacteria, Firmicutes and Actinobacteria, and most were isolated from contaminated sites, such as landfill sites. Just under a half of the studies (44%) investigated the biodegradability of polyethylenes and derivates, particularly low-density polyethylenes. The methods used to monitor the biodegradation were mainly scanning electron microscopy and Fourier-transform infrared spectroscopy. We propose that: (1) future research should focus on biodegradation of microplastics arising from the most common pollutants (e.g. polyethylenes); (2) bacteria should be isolated from environments that are permanently contaminated with plastics; and (3) a combination of different observational methods should be used to confirm bacterial biodegradation of these plastics. Finally, when reporting, researchers need to follow standard protocols and include all essential information needed for repetition of the experiments by other research groups.

Evaluation of a biocompatible sealant for on-demand repair of vascular defects-a chronic study in a large animal model

OBJECTIVES

Existing surgical sealants fail to combine design requirements, such as sealing performance, on-demand activation and biocompatibility. The aim of this study was to compare the effectiveness and safety of the SETALIUM™ Vascular Sealant (SVS), a novel, on-demand activatable sealant, with the commercial sealant, BioGlue®, for the repair of vascular defects.

METHODS

In an in vivo porcine model, the use of SVS was compared with BioGlue, for sealing 2-mm defects of the carotid artery and jugular vein. Animals were followed for 7 days and 5 weeks (each time point and per experimental group, n = 4), respectively. The degree of stenosis and flow velocity was determined, and the local tissue response was evaluated.

RESULTS

In vivo incision closure succeeded in all cases, and SVS was superior in clinical usability, enabled by its on-demand activation. Unlike BioGlue, SVS use did not induce stenosis and was associated with physiological blood flow in all cases. Moreover, closure with SVS was associated with a low inflammatory reaction and no thrombus formation or intima proliferation, in contrast to BioGlue.

CONCLUSIONS

SVS demonstrated effective and rapid sealing of 2-mm vascular defects, with favourable biocompatibility compared to BioGlue. Thus, SVS seems to be an effective and safe vascular sealant.

Freshwater insects of different feeding guilds ingest microplastics in two Gulf of Guinea tributaries in Nigeria

Plastic pollution has enormous impacts on freshwater and marine ecosystem health, and it is one of the topmost environmental concerns of the current geological period (i.e. the Anthropocene). Thus, the goal of our study was to provide baseline information and bridge the information gap on the occurrence of microplastics (MPs) in African freshwater systems, using two tributaries of the Gulf of Guinea (Ogun and Osun Rivers) in Nigeria as a case study and three freshwater insect species of different feeding guilds as bioindicators. A total of 29 individuals of the insect species were chemically digested and subsequently analysed for MP presence under a digital microscope and a micro-Fourier-transform infrared (μFTIR) spectroscope. Collector-gatherers (Chironomus sp. and Siphlonurus sp.) recorded the highest MP load per gram wet weight, while the predatory Lestes viridis recorded the lowest. The highest diversity of polymers was recorded in Chironomus sp. of Ogun River, i.e. styrene ethylene butylene styrene, acrylonitrile butadiene styrene (ABS), chlorinated polyethylene, polypropylene (PP), and polyester, while two polymers each were recorded in Siphlonurus sp. (i.e. polyester and ABS) and L. viridis (i.e. polyester and PP) of Osun River. We conclude that collector-gatherers like Chironomus sp. and Siphlonurus sp. could be best employed as MP bioindicators in freshwater systems. However, their suitability as MP bioindicators should be further investigated in different freshwater ecosystems worldwide. Graphical abstract.

Microplastics in sediments from an interconnected river-estuary region

Microplastics are an emerging pollutant of international concern due to its wide distribution through various pathways. Estuary is an important pathway for land microplastics to enter into the oceans by rivers. In this study, we hypothesized that microplastics would sink into estuary sediment during diffusion and transmission from river before entering into the sea, which results in higher accumulation of microplastics in proximity to river-estuary than in the oceans. In order to demonstrate this hypothesis, sediment samples were collected from an estuary and its two main inputting rivers and the microplastics in these samples were analyzed. In the collected sediment samples, 19 types of polymers, including the three most common polymers (polyethylene, polyethylene terephthalate, and poly(propylene:ethylene)), were identified and confirmed by FT-IR. Eight types of polymers were consistently detected in all samples, while 11 types of polymers were occasionally found in some samples. These microplastics exhibited four shapes and their percentages followed the high-to-low order of film, fragment, fiber and pellet. A relatively lower abundance of microplastics was found in river sediments from Shuangtaizi River with an average of 170 ± 96 particles/kg d.w., compared to that from Daliao River with an average of 237 ± 129 particles/kg d.w., but it was higher than that from Liaohe Estuary with an average of 120 ± 46 particles/kg d.w. Furthermore, the highest concentration of microplastics was found at the mouth of rivers, showing high accumulation where the freshwater and saltwater meet. Results from this study, including the abundance, characteristics and spatial distribution of microplastic pollution in sediments from an interconnected river-estuary system, revealed the fate and distribution of microplastics in the river and estuary environment.

PVC and PET microplastics in caddisfly (Lepidostoma basale) cases reduce case stability

Caddisfly larvae occur in streams and rivers, and many caddisfly species build protective cases using material from their habitat such as sand grains. At the same time, microplastics (MPs) are regularly deposited in aquatic sediments and are incorporated into caddisfly (Lepidostoma basale) cases in the field. However, it is unknown what the effects of MP incorporation into cases might be on the health of the caddisfly larvae. Hence, we offered two commonly used MPs (polyvinyl chloride (PVC) and polyethylene terephthalate (PET)) to L. basale larvae during a laboratory experiment. Both plastic types have a high density and co-occur with L. basale larvae in benthic habitats. In our experiment, L. basale actively used sand, PET and PVC MPs for building tube-like portable or emergency cases. The latter is a temporary shelter under which the larva can hide for immediate protection. Furthermore, case stability decreased with increasing PVC and PET particle content in the cases, suggesting that MPs may threaten caddisflies by destabilising cases. When case stability is reduced, the protective function of the cases is limited and the larvae may be more prone to predation. Additionally, larvae may be washed away by the current as plastic is lighter than sand. Both effects could limit the caddisfly's survival, which could have far-reaching consequences as caddisfly larvae are important primary consumers in aquatic ecosystems. Graphical abstract.

The presence of synthetic polymers in the maturation medium affects the cryotolerance and developmental capacity after parthenogenic activation of vitrified goat oocytes

The purpose of this present study is to assess if addition of the synthetic polymers in maturation medium can influence cryotolerance and subsequently embryonic development of mammalian oocytes. We examined the roles of two polymers, including polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP), on in vitro maturation (IVM), embryonic developmental capacity, and cryotolerance of goat oocytes. The present study includes two parts. At first, goat cumulus-oocyte complexes (COCs) were matured in a medium supplemented with 10% fetal bovine serum (FBS), 3 mg/ml PVP, or 1 mg/ml PVA, respectively. Data of oocyte with first polar body, cleavage, and blastocyst following parthenogenetic activation (PA) were recorded. Secondly, after maturation in the above medium, oocytes were vitrified using the Cryotop technique and then the morphology, cleavage and blastocyst formation of vitrified oocytes have been checked. The results demonstrated that the adding of PVP or PVA in maturation medium can't affect IVM of goat oocytes in comparison with FBS, as concern cumulus cell expansion, first polar body formation, and embryonic development. Additionally, without plunging into liquid nitrogen, only exposure to the vitrification and warming solutions cannot also influence the quality of oocytes, in terms of morphology, cleavage, and blastocyst formation. However, after IVM with synthetic polymers and vitrification, the ratio of oocytes with standard morphology in PVP or PVA group was only 59.47% ± 3.56% or 54.86% ± 5.19%, respectively, and was significantly less than that in the FBS group (89.37% ± 4.52%, P < 0.05). Furthermore, the cleavage ratio of oocytes in PVP or PVA group was 37.41% ± 4.17% or 27.71% ± 3.91% and was considerably less than that in the FBS group (64.97% ± 4.69%, P < 0.05). In addition, the cleavage ratio in PVP group was statistically higher than that in PVA group (P < 0.05). In terms of blastocyst development, a significant difference was observed between the synthetic polymer group and the FBS group (24.96% ± 3.62%, P < 0.05). However, the blastocyst ratio in the PVA group (7.51% ± 1.68%) was statistically less than the PVP groups (13.20% ± 4.59%, P < 0.05) and the FBS group (P < 0.05). In conclusion, two potential serum replacements, either PVP or PVA, can support IVM and embryonic development of goat oocytes at the concentration used in this study. But IVM with synthetic polymers supplemented to maturation medium may reduce the cryotolerance of oocytes. Additionally, the supportive function of PVP on embryonic development of vitrified oocytes might be better than that of PVA.

Mature biofilm communities on synthetic polymers in seawater - Specific or general?

To understand the ecological impacts of the "Plastisphere", those microbes need to be identified that preferentially colonize and interact with synthetic polymer surfaces, as opposed to general surface colonizers. It was hypothesized that the microbial biofilm composition varies distinctly between different substrates. A long-term incubation experiment was conducted (15month) with nine different synthetic polymer films as substrate as well as glass using a natural seawater flow-through system. To identify colonizing microorganisms, 16S and 18SrRNA gene tag sequencing was performed. The microbial biofilms of these diverse artificial surfaces were visualized via scanning electron microscopy. Biofilm communities attached to synthetic polymers are distinct from glass associated biofilms; apparently a more general marine biofilm core community serves as shared core among all synthetic polymers rather than a specific synthetic polymer community. Nevertheless, characteristic and discriminatory taxa of significantly different biofilm communities were identified, indicating their specificity to a given substrate.

Multiple Gas-Phase Conformations of a Synthetic Linear Poly(acrylamide) Polymer Observed Using Ion Mobility-Mass Spectrometry

Ion mobility-mass spectrometry (IM-MS) has emerged as a powerful separation and identification tool to characterize synthetic polymer mixtures and topologies (linear, cyclic, star-shaped,…). Electrospray coupled to IM-MS already revealed the coexistence of several charge state-dependent conformations for a single charge state of biomolecules with strong intramolecular interactions, even when limited resolving power IM-MS instruments were used. For synthetic polymers, the sample's polydispersity allows the observation of several chain lengths. A unique collision cross-section (CCS) trend is usually observed when increasing the degree of polymerization (DP) at constant charge state, allowing the deciphering of different polymer topologies. In this paper, we report multiple coexisting CCS trends when increasing the DP at constant charge state for linear poly(acrylamide) PAAm in the gas phase. This is similar to observations on peptides and proteins. Biomolecules show in addition population changes when collisionally heating the ions. In the case of synthetic PAAm, fragmentation occurred before reaching the energy for conformation conversion. These observations, which were made on two different IM-MS instruments (SYNAPT G2 HDMS and high resolution multi-pass cyclic T-Wave prototype from Waters), limit the use of ion mobility for synthetic polymer topology interpretations to polymers where unique CCS values are observed for each DP at constant charge state. Graphical Abstract ᅟ.

Polymer materials for prevention of postoperative adhesion

Postoperative adhesion (POA) is a common complication that often occurs after a variety of surgeries, such as plastic surgery, repair operations of abdominal, pelvic, and tendon, and so forth. Moreover, POA leads to chronic abdominal pain, secondary infertility in women, intestinal obstruction, and other severe complications, which significantly reduce the life quality of patients. In order to prevent the formation of POA, a number of strategies have been developed, among which an emerging method is physical barriers consisting of polymer materials. This review highlights the most commonly used natural and synthetic polymer materials in anti-adhesion physical barriers. The specific features of polymer materials are analyzed and compared, and the possible prospect is also predicted.

STATEMENT OF SIGNIFICANCE

Postoperative adhesion (POA) is a serious complication accompanied with various surgeries. Polymer material-based physical barriers have attracted a large amount of attention in POA prevention. The polymer barriers can effectively avoid the formation of fibrous tissues among normal organs by reducing the interconnection of injured tissues. In this review, specific features of the natural and synthetic polymer materials for application in POA prevention were presented, and the possible prospects were predicted. All in all, our work can provide inspiration for researchers to choose proper polymer materials for preclinical and even clinical anti-adhesion studies.

Polymers in our daily life

Polymers are widely used advanced materials, which are found almost in every material used in our daily life. To date, the importance of polymers has been much more highlighted because of their applications in different dominions of sciences, technologies and industry – from basic uses to biopolymers and therapeutic polymers. The main aim of this editorial is to accentuate the pragmatic impacts of polymers in human daily life.

Management of complication after breast augmentation with methacrylate

INTRODUCTION

Several alloplastic biomaterials are available for injection to the breast, nevertheless not all of them are approved for biomedical use. Although in North America and Western Europe experience with synthetic biomaterials for breast augmentation is very limited, migratory streams might expose physicians worldwide to manage the related complications of these procedures. The aim of this study was to share with other surgeons the case of a patient presenting complications after breast augmentation with an unknown synthetic substance containing methacrylate.

PRESENTATION OF CASE

A 33-years old Asian woman presented to our Institution with breast deformities, lumps and chest pain. The patient referred previous breast injection "with hospital fat" performed in China six years before. She was not aware about the details of the procedure, and language barriers limited communication. Clinical examination and ultrasounds revealed the irregular distribution of an unknown substance in both breasts. The material was surgically removed and replaced in the same session with polyurethane implants. Chemical analysis revealed the presence of methacrylate.

DISCUSSION

With a growing demand for non-invasive cosmetic surgery, has been reported a growing population of untrained and unlicensed personnel performing cosmetic surgery in many countries where there are no laws that restrict the use of cosmetic procedures to physicians with appropriate training and with approved materials. Surgical removal of this substances can be extremely challenging and an open procedure with surgical debridement is recommended.

CONCLUSION

Breast augmentation with non-absorbable biomaterials can lead to severe complications, in particular for patients intending to breastfeed.

Biocompatibility of poly(2-alkyl-2-oxazoline) brush surfaces for adherent lung cell lines

Development of synthetic surfaces that are highly reproducible and biocompatible for in vitro cell culture offers potential for development of improved models for studies of cellular physiology and pathology. They may also be useful in tissue engineering by removal of the need for biologically-derived components such as extracellular matrix proteins. We synthesised four types of 2-alkyl-2-oxazoline polymers ranging from the hydrophilic poly(2-methyl-2-oxazoline) to the hydrophobic poly(2-n-butyl-2-oxazoline). The polymers were terminated using amine-functionalised glass coverslips, enabling the synthetic procedure to be reproducible and scaleable. The polymer-coated glass slides were tested for biocompatibility using human epithelial (16HBE14o-) and fibroblastic (MRC5) cell lines. Differences in adhesion and motility of the two cell types was observed, with the poly(2-isopropyl-2-oxazoline) polymer equally supporting the growth of both cell types, whereas poly(2-n-butyl-2-oxazoline) showed selectivity for fibroblast growth. In summary, 2-alkyl-2-oxazoline polymers may be a useful tool for building in vitro model cell culture models with preferential adhesion of specific cell types.