Collagen-decorated electrospun scaffolds of unsaturated copolyesters for bone tissue regeneration.

Many efforts have been devoted to bone tissue to regenerate damaged tissues, and the development of new biocompatible materials that match the biological, mechanical, and chemical features required for this application is crucial. Herein, a collagen-decorated scaffold was prepared via electrospinning using a synthesized unsaturated copolyester (poly(globalide-co-pentadecalactone)), followed by two coupling reactions: thiol-ene functionalization with cysteine and further conjugation via EDC/NHS chemistry with collagen, aiming to design a bone tissue regeneration device with improved hydrophilicity and cell viability. Comonomer ratios were varied, affecting the copolymer's thermal and chemical properties and highlighting the tunable features of this copolyester. Functionalization with cysteine created new carboxyl and amine groups needed for bioconjugation with collagen, which is responsible for providing biological and structural integrity to the extra-cellular matrix. Bioconjugation with collagen turned the scaffold highly hydrophilic, decreasing its contact angle from 107 ± 2° to 0°, decreasing the copolymer crystallinity by 71%, and improving cell viability by 85% compared with the raw scaffold, thus promoting cell growth and proliferation. The highly efficient and biosafe strategy to conjugate polymers and proteins created a promising device for bone repair in tissue engineering.

Evaluation of berberine nanoparticles as a strategy to modulate acetylcholinesterase activity.

Researchers have concentrated efforts in the search for natural-based reversible inhibitors for cholinesterase enzymes as they may play a key role in the treatment of degenerative diseases. Diverse plant alkaloids can inhibit the action of acetylcholinesterase and, among them, berberine is a promising bioactive. However, berberine has poor water solubility and low bioavailability, which makes it difficult to use in treatment. The solid dispersion technique can improve the water affinity of hydrophobic substances, but berberine solid dispersions have not been extensively studied. Safety testing is also essential to ensure that the berberine-loaded solid dispersions are safe for use. This study investigated the effectiveness of berberine-loaded solid dispersions (SD) as inhibitors of acetylcholinesterase enzyme (AChE). Docking simulation was used to investigate the influence of berberine on AChE, and in vitro assays were conducted to confirm the enzymatic kinetics of AChE in the presence of berberine. Berberine SD also showed improved cytotoxic effects on tumoral cells when dispersed in aqueous media. In vivo assays using Allium cepa were implemented, and no cytotoxicity/genotoxicity was found for the berberine solid dispersion. These results suggest that berberine SD could be a significant step towards safe nanostructures for use in the treatment of neurodegenerative diseases.

Quantitative and functional characterisation of extracellular vesicles after passive loading with hydrophobic or cholesterol-tagged small molecules.

Extracellular vesicles (EVs) are nanosized intercellular messengers that bear enormous application potential as biological drug delivery vehicles. Much progress has been made for loading or decorating EVs with proteins, peptides or RNAs using genetically engineered donor cells, but post-isolation loading with synthetic drugs and using EVs from natural sources remains challenging. In particular, quantitative and unambiguous data assessing whether and how small molecules associate with EVs versus other components in the samples are still lacking. Here we describe the systematic and quantitative characterisation of passive EV loading with small molecules based on hydrophobic interactions - either through direct adsorption of hydrophobic compounds, or by membrane anchoring of hydrophilic ligands via cholesterol tags. As revealed by single vesicle imaging, both ligand types bind to CD63 positive EVs (exosomes), however also non-specifically to other vesicles, particles, and serum proteins. The hydrophobic compounds Curcumin and Terbinafine aggregate on EVs with no apparent saturation up to 106-107 molecules per vesicle as quantified by liquid chromatography - high resolution mass spectrometry (LC-HRMS). For both compounds, high density EV loading resulted in the formation of a population of large, electron-dense vesicles as detected by quantitative cryo-transmission electron microscopy (TEM), a reduced EV cell uptake and a toxic gain of function for Curcumin-EVs. In contrast, cholesterol tagging of a hydrophilic mdm2-targeted cyclic peptide saturated at densities of ca 104-105 molecules per vesicle, with lipidomics showing addition to, rather than replacement of endogenous cholesterol. Cholesterol anchored ligands did not change the EVs' size or morphology, and such EVs retained their cell uptake activity without inducing cell toxicity. However, the cholesterol-anchored ligands were rapidly shed from the vesicles in presence of serum. Based on these data, we conclude that (1) both methods allow loading of EVs with small molecules but are prone to unspecific compound binding or redistribution to other components if present in the sample, (2) cholesterol anchoring needs substantial optimization of formulation stability for in vivo applications, whereas (3) careful titration of loading densities is warranted when relying on hydrophobic interactions of EVs with hydrophobic compounds to mitigate changes in physicochemical properties, loss of EV function and potential cell toxicity.

Coating of SPIONs with a Cysteine-Decorated Copolyester: A Possible Novel Nanoplatform for Enzymatic Release.

Superparamagnetic iron oxide nanoparticles (SPIONs) have their use approved for the diagnosis/treatment of malignant tumors and can be metabolized by the organism. To prevent embolism caused by these nanoparticles, they need to be coated with biocompatible and non-cytotoxic materials. Here, we synthesized an unsaturated and biocompatible copolyester, poly (globalide-co-ε-caprolactone) (PGlCL), and modified it with the amino acid cysteine (Cys) via a thiol-ene reaction (PGlCLCys). The Cys-modified copolymer presented reduced crystallinity and increased hydrophilicity in comparison to PGlCL, thus being used for the coating of SPIONS (SPION@PGlCLCys). Additionally, cysteine pendant groups at the particle's surface allowed the direct conjugation of (bio)molecules that establish specific interactions with tumor cells (MDA-MB 231). The conjugation of either folic acid (FA) or the anti-cancer drug methotrexate (MTX) was carried out directly on the amine groups of cysteine molecules present in the SPION@PGlCLCys surface (SPION@PGlCLCys_FA and SPION@PGlCLCys_MTX) by carbodiimide-mediated coupling, leading to the formation of amide bonds, with conjugation efficiencies of 62% for FA and 60% for MTX. Then, the release of MTX from the nanoparticle surface was evaluated using a protease at 37 °C in phosphate buffer pH~5.3. It was found that 45% of MTX conjugated to the SPIONs were released after 72 h. Cell viability was measured by MTT assay, and after 72 h, 25% reduction in cell viability of tumor cells was observed. Thus, after a successful conjugation and subsequent triggered release of MTX, we understand that SPION@PGlCLCys has a strong potential to be treated as a model nanoplatform for the development of treatments and diagnosis techniques (or theranostic applications) that can be less aggressive to patients.

Membrane Manipulation of Giant Unilamellar Polymer Vesicles with a Temperature-Responsive Polymer.

Understanding the complex behavior and dynamics of cellular membranes is integral to gain insight into cellular division and fusion processes. Bottom-up synthetic cells are as a platform for replicating and probing cellular behavior. Giant polymer vesicles are more robust than liposomal counterparts, as well as having a broad range of chemical functionalities. However, the stability of the membrane can prohibit dynamic processes such as membrane phase separation and division. Here, we present a method for manipulating the membrane of giant polymersomes using a temperature responsive polymer. Upon elevation of temperature deformation and phase separation of the membrane was observed. Upon cooling, the membrane relaxed and became homogeneous again, with infrequent division of the synthetic cells.

Nanomedicine in leishmaniasis: A promising tool for diagnosis, treatment and prevention of disease - An update overview.

Leishmaniasis is a neglected tropical disease that has a wide spectrum of clinical manifestations, ranging from visceral to cutaneous, with millions of new cases and thousands of deaths notified every year. The severity of the disease and its various clinical forms are determined by the species of the causative agent, Leishmania, as well as the host's immune response. Major challenges still exist in the diagnosis and treatment of leishmaniasis, and there is no vaccine available to prevent this disease in humans. Nanotechnology has emerged as a promising tool in a variety of fields. In this review, we highlight the main and most recent advances in nanomedicine to improve the diagnosis and treatment, as well as for the development of vaccines, for leishmaniasis. Nanomaterials are nanometric in size and can be produced by a variety of materials, including lipids, polymers, ceramics, and metals, with varying structures and morphologies. Nanotechnology can be used as biosensors to detect antibodies or antigens, thus improving the sensitivity and specificity of such immunological and molecular diagnostic tests. While in treatment, nanomaterials can act as drug carriers or, be used directly, to reduce any toxic effects of drug compounds to the host and to be more selective towards the parasite. Furthermore, preclinical studies show that different nanomaterials can carry different Leishmania antigens, or even act as adjuvants to improve a Th1 immune response in an attempt to produce an effective vaccine.

Biopolymer-based nanocarriers for sustained release of agrochemicals: A review on materials and social science perspectives for a sustainable future of agri- and horticulture.

Devastating plant diseases and soil depletion rationalize an extensive use of agrochemicals to secure the food production worldwide. The sustained release of fertilizers and pesticides in agriculture is a promising solution to the eco-toxicological impacts and it might reduce the amount and increase the effectiveness of agrochemicals administration in the field. This review article focusses on carriers with diameters below 1 µm, such as capsules, spheres, tubes and micelles that promote the sustained release of actives. Biopolymer nanocarriers represent a potentially environmentally friendly alternative due to their renewable origin and biodegradability, which prevents the formation of microplastics. The social aspects, economic potential, and success of commercialization of biopolymer based nanocarriers are influenced by the controversial nature of nanotechnology and depend on the use case. Nanotechnology's enormous innovative power is only able to unfold its potential to limit the effects of climate change and to counteract current environmental developments if the perceived risks are understood and mitigated.

Evaluation of the in vivo acute toxicity of poly(thioether-ester) and superparamagnetic poly(thioether-ester) nanoparticles obtained by thiol-ene miniemulsion polymerization.

Poly(thioether-ester) (PTEe) nanoparticles obtained by thiol-ene polymerization have received attention of many researchers due to several advantages, including, biocompatibility and biodegradability. The search for new nanomaterials requires toxicity studies to assess potential toxic effects of their administration. Therefore, the aim of this study was to evaluate the in vivo acute toxicity of PTEe and poly(thioether-ester)-coated magnetic nanoparticles prepared by thiol-ene polymerization in miniemulsion. These nanoparticles presented a mean size of approximately 120 nm, spherical morphology, and negative surface charge. Doses of 40 mg/kg were administered intraperitoneally to Swiss mice and nociceptive, behavioral and biochemical parameters were investigated in five different organs. None of the nanoparticles led to any alterations in the nociceptive and behavioral responses. Biochemical alterations were observed in liver, decreasing the sulfhydryl and glutathione (GSH) levels, suggesting the dependence of the GSH metabolism in the elimination of the nanoparticles. In general, both nanoparticle types did not cause disturbances in biochemical parameters analyzed in others organs. These results suggest that both nanoparticle types did not induce acute toxicity to the different organs evaluated, reinforcing the biocompatibility of PTEe nanoparticles synthetized by thiol-ene polymerization.

Curcumin encapsulation in functional PLGA nanoparticles: A promising strategy for cancer therapies.

Nanoparticles have emerged as promising drug delivery systems for the treatment of several diseases. Novel cancer therapies have exploited these particles as alternative adjuvant therapies to overcome the traditional limitations of radio and chemotherapy. Curcumin is a natural bioactive compound found in turmeric, that has been reported to show anticancer activity against several types of tumors. Despite some biological limitations regarding its absorption in the human body, curcumin encapsulation in poly(lactic-co-glycolic acid) (PLGA), a non-toxic, biodegradable and biocompatible polymer, represents an effective strategy to deliver a drug to a tumor site. Furthermore, PLGA nanoparticles can be engineered with targeting moieties to reach specific cancer cells, thus enhancing the antitumor effects of curcumin. We herein aim to bring an up-to-date summary of the recently developed strategies for curcumin delivery to different types of cancer cells through encapsulation in PLGA nanoparticles, correlating their effects with those of curcumin on the biological capabilities acquired by cancer cells (cancer hallmarks). We discuss the targeting strategies proposed for advanced curcumin delivery and the respective improvements achieved for each cancer cell analyzed, in addition to exploring the encapsulation techniques employed. The conjugation of correct encapsulation techniques with tumor-oriented targeting design can result in curcumin-loaded PLGA nanoparticles that can successfully integrate the elaborate network of development of alternative cancer treatments along with traditional ones. Finally, the current challenges and future demands to launch these nanoparticles in oncology are comprehensively examined.

Cellulose nanocarriers via miniemulsion allow Pathogen-Specific agrochemical delivery.

The current spraying of agrochemicals is unselective and ineffective, consuming a high amount of fungicides, which endangers the environment and human health. Cellulose-based nanocarriers (NCs) are a promising tool in sustainable agriculture and suitable vehicles for stimuli-responsive release of agrochemicals to target cellulase-segregating fungi, which cause severe plant diseases such as Apple Canker. Herein, cellulose was modified with undec-10-enoic acid to a hydrophobic and cross-linkable derivative, from which NCs were prepared via thiol-ene addition in miniemulsion. During the crosslinking reaction, the NCs were loaded in situ with hydrophobic fungicides, Captan and Pyraclostrobin. NCs with average sizes ranging from 200 to 300 nm and an agrochemical-load of 20 wt% were obtained. Cellulose-degrading fungi, e.g. Neonectria. ditissima which is responsible for Apple Canker, lead to the release of fungicides from the aqueous NC dispersions suppressing fungal growth. In contrast, the non-cellulase segregating fungi, e.g. Cylindrocladium buxicola, do not degrade the agrochemical-loaded NCs. This selective action against Apple Canker fungi, N. ditissima, proves the efficacy of NC-mediated drug delivery triggered by degradation in the exclusive presence of cellulolytic fungi. Cellulose NCs represent a sustainable alternative to the current unselective spraying of agrochemicals that treats many crop diseases ineffectively.

Bovine Serum Albumin Conjugation in Superparamagnetic/Poly(methyl methacrylate) Nanoparticles as an Alternative for Magnetic Enzyme-Linked Immunosorbent Assays.

Nanomaterials, such as magnetic nanoparticles have attracted significant attention of medical area due to their capacity to improve the performance of immunoassays. Therefore the aim of this work was to study the bovine serum albumin (BSA) conjugation in superparamagnetic (MNPs)/poly(methyl methacrylate) (PMMA) nanoparticles with further characterization and application in enzyme-linked immunosorbent (ELISA) assay. The successful conjugation of BSA in MNPs- PMMA nanoparticles was confirmed by several techniques, including light scattering, zeta potential, transmission electron microscopy (TEM) and Lowry protein quantification assay. The superparamagnetic properties were confirmed by vibrating sample magnetometer. BSA conjugated MNPs-PMMA nanoparticles presented higher interactions with antibody than free BSA. The BSA + MNPs-PMMA nanoparticles (magnetic ELISA assay) reduced the time and increased the sensibility of traditional ELISA assay, reinforcing the idea that the use these nanomaterials are an excellent alternative for the immunoassays field.

In vitro synergic activity of diethyldithiocarbamate and 4-nitrochalcone loaded in beeswax nanoparticles against melanoma (B16F10) cells.

The use of nanoparticles as drug delivery systems to simultaneously carry several therapeutic agents is an attractive idea to create new synergic treatments and to develop the next generation of cancer therapies. Therefore, the goal of this study was the simultaneous encapsulation of a hydrophilic drug, sodium diethyldithiocarbamate (DETC), and a hydrophobic drug, 4-nitrochalcone (4NC), in beeswax nanoparticles (BNs) to evaluate the in vitro synergic activity of this combination against melanoma (B16F10) cells. BNs were prepared by water/oil/water double emulsion in the absence of organic solvents. Transmission electron microscopy imaging and dynamic light scattering analyses indicated the formation of BNs with a semispherical shape, average diameter below 250 nm, relatively narrow distributions, and negative zeta potential. The double emulsion technique proved to be effective for the simultaneous encapsulation of DETC and 4NC with efficiencies of 86.2% and 98.7%, respectively, and this encapsulation did not affect the physicochemical properties of the BNs. DETC and 4NC loaded in BNs exhibited a higher cytotoxicity toward B16F10 cells than free 4NC and DETC. This simultaneous encapsulation led to a synergic effect of DETC and 4NC on B16F10 cells, decreasing the cell viability from 46% (DETC BNs) and 54% (4NC BNs) to 64% (DETC+4NC BNs). Therefore, the IC50 of DETC+4NC was also lower than that of either when individually encapsulated, and that of free DETC or 4NC. Therefore, DETC and 4NC were efficiently simultaneously encapsulated in BNs and this drug combination was able to generate an in vitro synergic therapeutic effect on B16F10 cells.

Covalently Bonded N-Acetylcysteine-polyester Loaded in PCL Scaffolds for Enhanced Interactions with Fibroblasts.

Poly(ε-caprolactone) (PCL) is commonly used in devices for tissue reconstruction due to its biocompatibility and suitable mechanical properties. However, its high crystallinity and hydrophobicity do not favor cell adhesion and difficult polymer bioresorption. To improve these characteristics, the development of engineered scaffolds for tissue regeneration, based on poly(globalide-co-ε-caprolactone) (PGlCL) covalently bonded with N-acetylcysteine (PGlCL-NAC) was proposed. The scaffolds were obtained from polymer blends of PCL and PGlCL-NAC, using the electrospinning technique. The use of PGlCL-NAC allowed for the modification of the physical and chemical properties of PCL electrospun scaffolds, including an expressive reduction in the fiber's diameter, hydrophobicity, and crystallinity. All electrospun scaffolds showed no cytotoxicity against fibroblasts (McCoy cells). In vitro biocompatibility assays showed that all tested scaffolds provided high cell viability and proliferation in short-term (NRU, MTT, and nuclear morphology assays) and long-term (clonogenic assay) assays. Nevertheless, PGlCL-NAC based scaffolds have favored the survival and proliferation of the cells in comparison to PCL scaffolds. Cell adhesion on the scaffolds assessed by electronic microscopy images confirmed this behavior. These results suggest that the incorporation of PGlCL-NAC in scaffolds for tissue regeneration could be a promising strategy to improve cell-surface interactions and contribute to the development of more efficiently engineered biomedical devices.

Co-encapsulation of sodium diethyldithiocarbamate (DETC) and zinc phthalocyanine (ZnPc) in liposomes promotes increases phototoxic activity against (MDA-MB 231) human breast cancer cells.

There has been considerable interest in the development of novel photosensitisers for photodynamic therapy (PDT). The use of liposomes as drug delivery systems containing simultaneously two or more drugs is an attractive idea to create a new platform for PDT application. Therefore, the aim of this study was to evaluate the synergistic effect of diethyldithiocarbamate (DETC) and zinc phthalocyanine (PDT) co-encapsulated in liposomes. The reverse-phase evaporation method resulted in the successful encapsulation of DETC and ZnPc in liposomes, with encapsulation efficiencies above 85 %, mean size of 308 nm, and zeta potential of - 36 mV. The co-encapsulation decreased the cytotoxic effects in mouse embryo fibroblast (NIH3T3) cells and inhibited damage to human erythrocytes compared to free DETC + ZnPc. In addition, both the free drugs and co-encapsulated ones promoted more pronounced phototoxic effects on human breast cancer cells (MDA-MB231) compared to treatment with ZnPc alone. This synergistic effect was determined by DETC-induced decreases in the antioxidant enzyme activity of superoxide dismutase (SOD) and glutathione (GSH).

4-nitrochalcone exerts leishmanicidal effect on L. amazonensis promastigotes and intracellular amastigotes, and the 4-nitrochalcone encapsulation in beeswax copaiba oil nanoparticles reduces macrophages cytotoxicity.

The Leishmaniasis treatment currently available involves some difficulties, such as high toxicity, variable efficacy, high cost, therefore, it is crucial to search for new therapeutic alternatives. Over the past few years, research on new drugs has focused on the use of natural compounds such as chalcones and nanotechnology. In this context, this research aimed at assessing the in vitro leishmanicidal activity of free 4-nitrochalcone (4NC) on promastigotes and encapsulated 4NC on L. amazonensis-infected macrophages, as well as their action mechanisms. Free 4NC was able to reduce the viability of promastigotes, induce reactive oxygen species production, decrease mitochondrial membrane potential, increase plasma membrane permeability, and expose phosphatidylserine, in addition to altering the morphology and lowering parasite cellular volume. Treatment containing encapsulated 4NC in beeswax-copaiba oil nanoparticles (4NC-beeswax-CO Nps) did not alter the viability of macrophages. Furthermore, 4NC-beeswax-CO Nps reduced the percentage of infected macrophages and the number of amastigotes per macrophages, increasing the production of reactive oxygen species, NO, TNF-α, and IL-10. Therefore, free 4NC proved to exert anti-promastigote effect, while 4NC-beeswax-CO Nps showed a leishmanicidal effect on L. amazonensis-infected macrophages by activating the macrophage microbicidal machinery.

Diethyldithiocarbamate encapsulation reduces toxicity and promotes leishmanicidal effect through apoptosis-like mechanism in promastigote and ROS production by macrophage.

The use of compounds from natural or synthetic sources and nanotechnology may represent an alternative to develop new drugs for the leishmaniasis treatment. DETC is an inhibitor of the SOD1 enzyme, which leads to increased ROS production, important for the elimination of Leishmania. Thus, our objective was to assess the leishmanicidal in vitro effect of free Diethydithiocarbamate (DETC) and DETC loaded in beeswax-copaiba oil nanoparticles (DETC-Beeswax-CO Nps) on L. amazonensis forms and elucidate the possible mechanisms involved in the parasite death. DETC-Beeswax-CO Nps presented size below 200 nm, spherical morphology, negative zeta potential, and high encapsulation efficiency. Free DETC reduced the viability of promastigotes and increase ROS production, lower the mitochondrial membrane potential, cause phosphatidylserine exposure, and enhance plasma membrane permeability, in addition to promoting morphological changes in the parasite. Free DETC proved toxic in the assessment of toxicity to murine macrophages, however, the encapsulation of this compound was able to reduce these toxic effects on macrophages. DETC-Beeswax-CO Nps exerted anti-amastigote effect by enhancing the production of ROS, superoxide anion, TNF-α, IL-6, and reduced IL-10 in macrophages. Therefore, free DETC induces antipromastigote effect by apoptosis-like; and DETC-Beeswax-CO Nps exerted anti-leishmanial effect due to pro-oxidant and pro-inflammatory response.

Bio-Based Lignin Nanocarriers Loaded with Fungicides as a Versatile Platform for Drug Delivery in Plants.

Lignin-based nano- and microcarriers are a promising biodegradable drug delivery platform inside of plants. Many wood-decaying fungi are capable of degrading the wood component lignin by segregated lignases. These fungi are responsible for severe financial damage in agriculture, and many of these plant diseases cannot be treated today. However, enzymatic degradation is also an attractive handle to achieve a controlled release of drugs from artificial lignin vehicles. Herein, chemically cross-linked lignin nanocarriers (NCs) were prepared by aza-Michael addition in miniemulsion, followed by solvent evaporation. The cross-linking of lignin was achieved with the bio-based amines (spermine and spermidine). Several fungicides-namely, azoxystrobin, pyraclostrobin, tebuconazole, and boscalid-were encapsulated in situ during the miniemulsion polymerization, demonstrating the versatility of the method. Lignin NCs with diameters of 200-300 nm (determined by dynamic light scattering) were obtained, with high encapsulation efficiencies (70-99%, depending on the drug solubility). Lignin NCs successfully inhibited the growth of Phaeomoniella chlamydospora and Phaeoacremonium minimum, which are lignase-producing fungi associated with the worldwide occurring fungal grapevine trunk disease Esca. In planta studies proved their efficiency for at least 4 years after a single injection into Vitis vinifera ("Portugieser") plants on a test vineyard in Germany. The lignin NCs are of high interest as biodegradable delivery vehicles to be applied by trunk injection against the devastating fungal disease Esca but might also be promising against other fungal plant diseases.

Antitumor activity associated with hyperthermia and 4-nitrochalcone loaded in superparamagnetic poly(thioether-ester) nanoparticles.

The combination of hyperthermia and chemotherapy has a potential synergic effect in antitumor activity. The development of new biocompatible and biodegradable polymers to simultaneously encapsulate magnetic nanoparticles (MNPs) and antitumoral drugs offer new cancer treatment opportunities. Here, biodegradable and biocompatible poly(thioether-ester) (PTEe) was used to encapsulate MNPs and 4-nitrochalcone (4NC) using miniemulsification and solvent evaporation. The resulting hybrid particles (MNPs-4NC-PTEe) had nanometer-scale diameters, spherical morphology, negative surface charge, high encapsulation efficiency, and superparamagnetic properties. Results showed that 4NC release occurred through diffusion. Free 4NC and MNPs + 4NC-PTEe did not have any cytotoxic effect on erythrocytes and mouse embryonic fibroblast (NIH3T3) cells. 4NC antitumor activity was verified on human cervical cancer (HeLa) and melanoma (B16F10) cells. Cellular uptake of MNPs + 4NC-PTEe nanoparticles was higher in HeLa cells compared to B16F10 and NIH3T3 cells. The hyperthermia application (115 kHz-500 Oe) potentiated the 4NC effects on HeLa and B16F10 cells when MNPs + 4NC-PTEe nanoparticles were used, indicating more effective antitumor activity. We concluded that the use of MNPs + 4NC-PTEe nanoparticles associated with hyperthermia is a promising form of treatment for some types of cancers.

Immobilization of lipase Eversa Transform 2.0 on poly(urea-urethane) nanoparticles obtained using a biopolyol from enzymatic glycerolysis.

In this work, the free lipase Eversa® Transform 2.0 was used as a catalyst for enzymatic glycerolysis reaction in a solvent-free system. The product was evaluated by nuclear magnetic resonance (1H NMR) and showed high conversion related to hydroxyl groups. In sequence, the product of the glycerolysis was used as stabilizer and biopolyol for the synthesis of poly(urea-urethane) nanoparticles (PUU NPs) aqueous dispersion by the miniemulsion polymerization technique, without the use of a further surfactant in the system. Reactions resulted in stable dispersions of PUU NPs with an average diameter of 190 nm. After, the formation of the PUU NPs in the presence of concentrated lipase Eversa® Transform 2.0 was studied, aiming the lipase immobilization on the NP surface, and a stable enzymatic derivative with diameters around 231 nm was obtained. The hydrolytic enzymatic activity was determined using ρ-nitrophenyl palmitate (ρ-NPP) and the immobilization was confirmed by morphological analysis using transmission electron microscopy and fluorescence microscopy.

Crosslinking of Electrospun Fibres from Unsaturated Polyesters by Bis-Triazolinediones (TAD).

Crosslinking of an unsaturated aliphatic polyester poly(globalide) (PGl) by bistriazolinediones (bisTADs) is reported. First, a monofunctional model compound, phenyl-TAD (PTAD), was tested for PGl functionalisation. 1H-NMR showed that PTAD-ene reaction was highly efficient with conversions up to 97%. Subsequently, hexamethylene bisTAD (HM-bisTAD) and methylene diphenyl bisTAD (MDP-bisTAD) were used to crosslink electrospun PGl fibres via one- and two-step approaches. In the one-step approach, PGl fibres were collected in a bisTAD solution for in situ crosslinking, which resulted in incomplete crosslinking. In the two-step approach, a light crosslinking of fibres was first achieved in a PGl non-solvent. Subsequent incubation in a fibre swelling bisTAD solution resulted in fully amorphous crosslinked fibres. SEM analysis revealed that the fibres' morphology was uncompromised by the crosslinking. A significant increase of tensile strength from 0.3 ± 0.08 MPa to 2.7 ± 0.8 MPa and 3.9 ± 0.5 MPa was observed when PGI fibres were crosslinked by HM-bisTAD and MDP-bisTAD, respectively. The reported methodology allows the design of electrospun fibres from biocompatible polyesters and the modulation of their mechanical and thermal properties. It also opens future opportunities for drug delivery applications by selected drug loading.