Removal of Cd(II), Co(II), Cr(III), Ni(II), Pb(II) and Zn(II) ions from wastewater using polyethyleneimine (PEI) cryogels.

The removal of the target analytes, Cd(II), Co(II), Cr(III), Ni(II), Pb(II), and Zn(II) from contaminated waters was achieved using super porous polyethyleneimine (PEI) cryogels as adsorbent. The optimum values of the sample pH and contact time were determined as 4.0 and 90 min, respectively, for the removal of the analytes. The adsorption capacities of the sorbent were between 19.88 and 24.39 mgg-1 from 10 mL of 50 mgL-1 target metal ion solutions. The sorption kinetics of metal ions were fitted with the pseudo-second-order model. The adsorption isotherms of the target analytes into PEI cryogel were well-fitted to the Langmuir isotherm model as expected from the material homogeneity. The selectivity of the PEI cryogel in the presence of Na+, Ca2+, Mg2+, NO3-, K+ and Cl- ions even at high concentrations was tested, and the tolerance limits were satisfactory enough, e.g., the adsorption of the target analytes was even not affected in the presence of 2000 mgL-1 Ca2+, K+, Na+, Cl- and 5000 mgL-1 NO3- ions. The PEI cryogels were successfully utilized in different industrial wastewater samples that were spiked with a known amount of analytes. The removal of the analytes from wastewater samples was in the following ranges 91.94-99.86% for Cd(II), 89.59-99.89% for Co(II), 80.35-99.76% for Cr(III), 92.02-99.84% for Ni(II), 83.28-99.86% for Pb(II), and 82.94-98.24% for Zn(II), respectively. The presented novel removal strategy offers a selective, efficient, and easy application for target metal ions from industrial wastewater samples.

Self-Crosslinked Ellipsoidal Poly(Tannic Acid) Particles for Bio-Medical Applications.

Self-crosslinking of Tannic acid (TA) was accomplished to obtain poly(tannic acid) (p(TA)) particles in single step, surfactant free media using sodium periodate (NaIO4) as an oxidizing agent. Almost monodisperse p(TA) particles with 981 ± 76 nm sizes and -22 ± 4 mV zeta potential value with ellipsoidal shape was obtained. Only slight degradation of p(TA) particles with 6.8 ± 0.2% was observed at pH 7.4 in PBS up to 15 days because of the irreversible covalent formation between TA units, suggesting that hydrolytic degradation is independent from the used amounts of oxidation agents. p(TA) particles were found to be non-hemolytic up to 0.5 mg/mL concentration and found not to affect blood clotting mechanism up to 2 mg/mL concentration. Antioxidant activity of p(TA) particles was investigated by total phenol content (TPC), ferric reducing antioxidant potential (FRAP), trolox equivalent antioxidant capacity (TEAC), total flavanoid content (TFC), and Fe (II) chelating activity. p(TA) particles showed strong antioxidant capability in comparison to TA molecules, except FRAP assay. The antibacterial activity of p(TA) particles was investigated by micro-dilution technique on E. coli as Gram­negative and S. aureus as Gram-positive bacteria and found that p(TA) particles are more effective on S. aureus with over 50% inhibition at 20 mg/mL concentration attained.

Delivery of Small Molecule EF2 Kinase Inhibitor for Breast and Pancreatic Cancer Cells Using Hyaluronic Acid Based Nanogels.

PURPOSE: To evalauted natural polymeric biomaterials including hyaluronic acid (HA) and its copolymeric form HA:Suc nanoparticles (NPs) as drug carrier systems for delivery of hydrophobic small molecule kinase EF2-kinase inhibitor in breast and pancreatic cancer cells. METHODS: In vitro cellular uptake studies of Rhodamine 6G labaled HA:Suc nanoparticles were evaluated by using flow cytometry analysis and fluorescent microscopy in breast (MDA-MB-231 and MDA-MB-436) and pancreatic cancer cells (PANC-1 and MiaPaca-2). Besides, in vitro release study of compound A (an EF2-kinase inhibitor) as a model hydrophobic drug was performed in the cancer cells. RESULTS: These biological evaluation studies indicated that HA and HA:Suc NPs provided a highly effective delivery of compound A were into breast and pancreatic cancer cells, leading to significant inhibition of cell proliferation and colony formation of breast and pancreatic cancer cells. CONCLUSION: HA-sucrose NPs incorporating an EF2-Kinase inhibitor demonstrate significant biologic activity in breast and pancreatic cancer cells. This is the first study that shows natural polymeric drug carriers succesfully deliver a hydrofobic cancer drug into cancer cells. Graphical Abstract Nanoparticles based on HA:Suc are effective in delivering hydrofobic cancer drugs in breast and pancreatic cancers.

Nitrogen and Sulfur Doped Carbon Dots from Amino Acids for Potential Biomedical Applications.

Nitrogen (N-) and sulfur (S-) doped carbon dots (CDs) were synthesized in a single step in a few min, 1-4 min via microwave technique from five different types of amino acids viz. Arginine (A), Lysine (L), Histidine (H), Cysteine (C), and Methionine (M). These amino acid derived N- and/or S- doped CDs were found to be in spherical shapes with 5-20 nm particle size range determined by Transition Electron Microscope (TEM) images and Dynamic Light Scattering (DLS) measurements. Thermal degradation, functional groups, and surface potential of the CDs were determined by Thermogravimetric Analysis (TGA), FT-IR spectroscopy, and zeta potential measurements, respectively. Although the zeta potential value of Cysteine derived CD (C-CD) was measured as -7.45±1.32 mV, the zeta potential values of A-CD, L-CD, H-CD, and M-CD particles were measured as +2.84±0.67, +2.61±1.0, +4.10±1.50 and+2.20±0.60 mV, respectively. Amongst the CDs, C- CDs was found to possess the highest quantum yield, 89%. Moreover, the blood compatibility test of CDs, determined with hemolysis and blood clotting tests was shown that CDs at 0.25 mg/mL concentration, CDs has less than 5% hemolysis ratio and higher than 50% blood clotting indexes. Furthermore, A-CD was modified with polyethyleneimine (PEI) and was found that the zeta potential values was increased to +34.41±4.17 mV (from +2.84±0.67 mV) inducing antimicrobial capability to these materials. Minimum Inhibition Concentration (MIC) of A-CD dots was found as 2.5 mg/mL whereas the PEI modified A-CDs, A-CD-PEI was found as 1 mg/mL against Escherichia coli ATCC 8739 (gram -) and Staphylococcus aureus ATCC 6538 (gram +) bacteria strains signifying the tunability of CDs.

Fast removal of high quantities of toxic arsenate via cationic p(APTMACl) microgels.

Hydrogels are resourceful materials and can be prepared in different morphology, size, surface charge and porosity adopting different polymerization techniques and reaction conditions. The cationic poly(3-acrylamidopropyl)trimethylammonium chloride (p(APTMACl)) microgels were synthesized by photo-initiated inverse suspension polymerization technique. These microgels were utilized as absorbents for the removal of toxic arsenate (As) from different aqueous environments. The experimental parameters affecting absorption efficiency were investigated, and it was demonstrated that these types of microgels are highly efficient in removing arsenate anions from different aqueous environments compared to the previously reported bulk hydrogel, and cryogel of the same material. A removal efficiency of approximately 97.25% was obtained by immersing 0.5 g microgel in 250 ppm 100 mL solution of arsenate anions for 60 min. Both Langmuir and Freundlich adsorption isotherms were applied to adsorption of arsenate anions by p(APTMACl) microgels, and the Langmuir isotherm was a better representation of the adsorption of arsenate with a high value of R(2) (0.9982). Furthermore, mag-p(APTMACl) microgels were synthesized for the adsorption of arsenate anions to provide easy removal of the microgel composite by using an externally applied magnetic field. Furthermore, re-usability of the p(APTMACl) microgels was also investigated for the adsorption of arsenate anions.

Nontoxic Natural Polymeric Particle Vehicles Derived from Hyaluronic Acid and Mannitol as Mitomycin C Carriers for Bladder Cancer Treatment.

Hyaluronic acid/mannitol (HA/MN)-based particles were designed as mitomycin c (MMC) delivery vehicles through the crosslinking of 1:0, 3:1, 1:3, and 0:1 mole ratios of HA/MN to investigate their potential use in bladder cancer therapy. The HA/MN-MMC particles prepared by the microemulsion crosslinking method were of 0.5-10 µm size with a zeta potential value of -36.7 mV. The MMC carrier potential of the HA/MN-MMC particles was investigated by changing HA/MN ratios in the particle structure. The MMC loading capacity of neat HA particles was 5.3 ± 1.1 mg/g, whereas HA/MN (1:3) particles could be loaded with about three times more drug, for example, 18.4 ± 0.8 mg/g. The kinetic of MMC drug delivery from the HA/MN-MMC particles were tested in vitro in bladder cancer conditions for example, pH 4.5, 6, and 7.4. The HA-MMC particles released approximately 70% of the loaded drug in 300 h, while 43% of the loaded drug was released from the HA/MN-MMC particles within 600 h under physiological conditions, pH 7.4, 37 °C. The cytotoxicity of HA-based particles on healthy L929 fibroblast cells and HTB-9 human bladder cancer cells was investigated in vitro via MTT tests. Bare MMC inhibited about 90% of L929 fibroblast cells even at 100 µg/mL, but the cell viabilities in the presence of HA-MMC and HA/MN-MMC particles were 85 ± 5 and 109 ± 7% at 1000 µg/mL, respectively. The HA/MN-MMC (1:3) particles at 1000 µg/mL were found capable of destroying half of HTB-9 human bladder cancer cells within 24 h. Interestingly, the same particles at 50 µg/mL destroyed almost all the cancer cells with 8 ± 5% cell viability in 72 h of incubation time. The designed HA/MN-MMC (1:3) particles were found to afford a chemotherapeutic effect on the tumor cancers while reducing the toxicity of MMC against L929 fibroblast cells.

Biocompatible poly(galacturonic acid) micro/nanogels with controllable degradation via tunable chemical crosslinking.

Here, one-pot labor-less preparation of two different polygalacturonic acid (PGA) micro/nanogel formulations, PGA-1 and PGA-2, by respectively crosslinking the PGA chains with divinyl sulfone (DVS) and trimethylolpropane triglycidyl ether (TMPGDE) were reported. Various crosslinker ratios, 2.5, 10, 50, and 100% were used for both crosslinkers to demonstrate the tunability of their degradation properties. The PGA micro/nanogels were found spherical-shaped porous particles in 0.5-5.0 µm size range by SEM. The hydrolytic degradation and stability of PGA micro/nanogels in pH 1.0, 7.4, and 9.0 buffer solutions can be controlled by changing the degree of crosslinking. Accordingly, 32 ± 8% and 36 ± 2% weight losses were attained for PGA-1-10% and PGA-2-10% micro/nanogels at pH 1, respectively, and 46 ± 6%, and 68 ± 6% degradations were determined at pH 7.4 within 4 weeks. However, no degradation was observed for both PGA-based micro/nanogel formulations prepared at 25% and 100% crosslinker ratios at all pH conditions. All PGA-based micro/nanogels were totally degraded within 7-10 days at pH 9.0. In the presence of pectinase and amyloglucosidase enzymes, all formulations of PGA micro/nanogels showed more than 80% degradation within 12 h. Furthermore, both PGA formulations showed no significant cytotoxicity against L929 fibroblast cells with 90% and above cell viability up to 250 mg/mL concentrations.

Fungal Keratitis Treatment Using Drug-Loaded Hyaluronic Acid Microgels.

Antifungal drug-loaded hyaluronic acid (HA) microgels using conjugation and encapsulation drug-loading techniques were utilized in the treatment of fungal keratitis. Natamycin (NAT) and amphotericin B (AMB) drugs were chemically linked to HA microgels by employing a chemical coupling agent to obtain conjugated (C-) HA:NAT and HA:AMB microgels. Also, these drugs were loaded into the HA microgel network during HA microgel preparation to attain encapsulated (E-) HA:NAT and HA:AMB microgels. The conjugation of drug molecules was confirmed by FT-IR spectra of bare and drug-loaded HA microgels. It was determined that the AMB loading amount was about 4-fold higher for E-HA:AMB in comparison to C-HA:AMB microgels. Furthermore, the antifungal activity of drug conjugated and encapsulated HA:NAT and HA:AMB microgels was tested on Fusarium sp. and compared with the effect of bare drug molecules as control for up to 15 days of incubation time by means of the disc diffusion technique. The antifungal activity of 200 µL at 20 mg/mL concentration of C-HA:NAT and C-HA:AMB microgels was not found to effectively inhibit Fusarium sp. growth after 1 day of incubation, whereas the same concentration of E-HA:NAT and E-HA:AMB microgels totally killed Fusarium sp. for up to 15 days. These E-HA:NAT and E-HA:AMB microgels show no cytotoxicity on the L929 fibroblast cells up to 1000 µg/mL concentration, whereas the free drug molecules destroy the cells even at 100 µg/mL concentration.

A facile one-pot synthesis of microgels and nanogels of laminarin for biomedical applications.

HYPOTHESIS: Laminarin (LAM) as a nontoxic, biodegradable, and biocompatible marine polysaccharide, has been reported for its ingenious bioactivities such as antioxidant, antitumor antiapoptotic anti-inflammatory, immunomodulatory and dietary fiber activities, and distinct physicochemical structure possess a remarkably promising potential in biomaterial science. Synthesis of LAM-based microgels and bulk hydrogels have been reported in two stages: modification of LAM polysaccharide with polymerizable functional groups and subsequent crosslinking reaction. Therefore, here an easier and more effortless methods to prepare poly(laminarin) (p(LAM)) particles were tackled. EXPERIMENTAL: A direct and facile single step fabrication of micro/nanogels of p(LAM) for the first time by means of reverse micelle microemulsion system were illustrated. Preparation of p(LAM) particles were achieved by the well-known Oxa-Michael addition reaction mechanism using divinyl sulfone as the crosslinker. FINDINGS: P(LAM) particles in 0.3-10 µm size range in spherical morphologies were prepared with 93 ± 7% yield and functionalized with chlorosulfonic acid (CSA) demonstrating their chemical modifiability for variety of agents e.g., targeting ligands. The bare and modified p(LAM) particles showed excellent blood compatibility with hemolytic indices of <1% and blood clotting indices higher than 90%. The reported p(LAM) particles hold great promise as natural alternative surrogates in biomedical applications including drug delivery.

Crosslinked poly(Lactose) microgels and nanogels for biomedical applications.

HYPOTHESIS: Lactose (LAC) is a primary carbohydrate and energy source of milk has received intensive attention due to its' unique functional and nutritional properties. Many biological beneficences of LAC make it an appealing molecule to seek for designing functional interfaces. Therefore, crosslinked poly(lactose) (p(LAC)) microgel from lactose disaccharides for potential biomedical applications was pursued as biocolloids for the first time. EXPERIMENT: p(LAC) microgels prepared by chemical crosslinking with DiVinyl Sulfone (DVS) were chemically modified with ethylenediamine (EDA) to obtain amine-modified p(LAC) (p(LAC)-EDA) microgels to induce new functionalities and properties. Blood compatibilities of bare p(LAC)-EDA microgels were tested through hemolysis and blood clotting tests. Rosmarinic acid (RA) used as a model drug was loaded into p(LAC) and p(LAC)-EDA microgels to demonstrate their applicability to be used in drug loading and release applications. FINDINGS: A facile preparation of p(LAC) microgels with high yield, 90 ±â€¯5% and 0.5-50 µm size range was accomplished via water-in-oil (w/o) microemulsion crosslinking method. Upon chemical modification, the isoelectric point (IEP) from pH 1.8 for p(LAC) microgels changed to pH 7.7 for p(LAC)-EDA microgels, and the blood compatibility studies revealed that both microgels can be considered as blood compatible up to 2 mg/mL concentration, and only slight decrease in blood clotting index (BCI) of p(LAC)-EDA microgels was observed. Rosmarinic Acid (RA) was demonstrated to be released up to 4 days in phosphate buffer saline (PBS) with a linear release profile for p(LAC)-EDA microgels.

Hyaluronic acid and hyaluronic acid: Sucrose nanogels for hydrophobic cancer drug delivery.

Porous and biodegradable hyaluronic acid (HA) nanogel and their copolymeric forms with sucrose (Suc), HA:Sucrose (HA:Suc) nanogels, were synthesized by employing glycerol diglycidyl ether (GDE) as crosslinker with a single step reaction in surfactant-free medium. The size of the nanogels was determined as 150 ±â€¯50 nm in dried state from SEM images and found to increase to about 540 ±â€¯47 nm in DI water measured with DLS measurements. The surface areas of HA and HA:Suc nanogels were measured as 18.07 ±â€¯2.4 and 32.30 ±â€¯6.1 m2/g with porosities of 3.58 ±â€¯1.8, and 9.44 ±â€¯3.1 nm via BET analysis, respectively. The zeta potentials for HA and HA:Suc nanogels were measured as -33 ±â€¯1.4 and - 30 ±â€¯1.2 mV, respectively. The thermal degradation of both types of nanogels revealed similar trends, while hydrolytic degradation of the nanogels was about 22.7 ±â€¯0.2 wt% in 15 days. Both HA and HA:Suc nanogels were stable in blood up to 250 µg/mL concentration with approximately 0.5 ±â€¯0.1% hemolysis ratio and 76 ±â€¯12% blood clotting indices, respectively. Finally, these nanogels were used as a sustained slow-release or long-term delivery system over 2 days for a hydrophobic cancer drug, 3­((E)­3­(4­hydroxyphenyl)acryloyl)­2H­chromen­2­on (A#) established by our group. The nanogels successfully delivered the model drug A at 10.43 ±â€¯2.12 mg/g for 2 days.

Enhancement of biocompatibility and carbohydrate absorption control potential of rosmarinic acid through crosslinking into microparticles.

Rosmarinic acid (RA), a bioflavonoid and antioxidant that exists in plants of the Lamiaceae family, was crosslinked into particles as poly(Rosmarinic Acid) (p(RA)) via an emulsion crosslinking method. The particles were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, solid state nuclear magnetic resonance 13C NMR spectroscopy, and thermal gravimetric analysis. The zeta potential values of p(RA) particles were determined at different pHs; the isoelectric point was estimated as pH 1.2. The release of monomeric RA from the particles at 37.5 °C was found to be similar at different pHs, 1.0, 7.4, and 11.0. The effects of p(RA) on hemolysis and coagulation were found to be minimal. The antioxidant activity of p(RA) particles and RA monomer were almost indistinguishable suggesting that p(RA) particles may be used as an antioxidant. On a per weight basis, p(RA) particles were ~66% less cytotoxic to mammalian cells that RA monomer, as assessed using COS-1 cells. In addition, p(RA) was an 8.6-fold stronger inhibitor of α-glycosidase than RA; the IC50s of the monomer and particles were 0.121 and 0.014 mg/mL, respectively. The strong inhibitory effect of p(RA) on α-glycosidase, coupled with its reduced cytotoxicity and antioxidant activity, provide new opportunities for the use of p(RA).

Cryogel composites based on hyaluronic acid and halloysite nanotubes as scaffold for tissue engineering.

We present here preparation of mechanically strong and biocompatible cryogel composites based on hyaluronic acid (HA) and halloysite nanotubes (HNTs) of various compositions, and their applications as scaffold for different cell growing media. Uniaxial compression tests reveal that the incorporation of HNTs into HA cryogels leads to a ~2.5-fold increase in their Young moduli, e.g., from 38 ±â€¯1 to 99 ±â€¯4 kPa at a HA:HNTs weight ratio of 1:2. Although HA:HNTs based cryogels were found to be blood compatible with 1.37 ±â€¯0.11% hemolysis ratio at a HA:HNTs weight ratio of 1:2, they trigger thrombogenic activity with a blood clotting index of 17.3 ±â€¯4.8. Remarkably, HA:HNTs cryogel composites were found to be excellent scaffold materials in the proliferation of rat mesenchymal stem cells (MSC), human cervical carcinoma cells (HeLa), and human colon cancer cells (HCT116). The cell studies revealed that an increased amount of HNT embedding into HA cryogels leads to an increase of MSC proliferation.

One step preparation of polymeric maltitol particles, from a sugar molecule, maltitol for biomedical applications.

Here, a facile method for the preparation of polymeric particles from a sugar molecule, maltitol (ML) in single step was reported via microemulsion polymerization/crosslinking technique with a high yield, 89 ±â€¯6%. Furthermore, poly(Maltitol) (p(ML)) particles were chemically modified to induce different physicochemical characteristic using different anionic and cationic modifying agents such as taurine (TA) and diethylenetriamine (DETA) to prepare m-p(ML)/TA and m-p(ML)/DETA. The blood compatibility of the p(ML) particles and their modified forms were tested with fresh blood, and found that p(ML) and m-(ML)/DETA particles are blood compatible with about 5% hemolysis, and above 80% blood clotting indices. Moreover, the cytotoxicity results against L929 fibroblast cell line revealed that p(ML) based particle are biocompatible up to 100 µg/mL with 85% cell viability regardless of their nature, and at 200 µg/mL dosage of p(ML), m-p(ML)/TA and m-p(ML)/DETA particles, the cell viabilities were determined as 83.33, 64.03 and 73.89% on for L929 fibroblast cells implying the slightly less biocompatibility nature of m-p(ML)/TA in accord with the blood compatibility results. Additionally, the apoptotic and necrotic indices were determination for p(ML) based particles on L929 fibroblast cells, and the results revealed that these particles do not induce any and stress on the cells. Also, it does not have genotoxic effect as determined against CHO cells.

Polydopamine particles as nontoxic, blood compatible, antioxidant and drug delivery materials.

Herein, the potential biomedical application of poly(3,4-dihyroxyphenyl)ethylamine, (poly(dopamine)-p(DA)) particles is reported. P(DA) particles with the size about 100 nm, 18.05 m2/g specific surface area, and mesoporous structure (7.19 nm pore width) were prepared and shown to be chemically modifiable using chlorosulfonic acid (CSA) and 3-CHloro-2 hydroxypropyl) trimethylammonium chloride solution (CHPACl) to obtain sulfonic acid and quaternary amine group containing modified p(DA) particles, m-p(DA)-CSA and m-p(DA)-CHPACl particles, respectively. The hydrolytic degradation of p(DA) particles at different pHs, including 1, 7.4 and 11, was carried out at 37.5 °C. These degradation studies revealed that p(DA) is slightly degradable at pH 1 and pH 7.4 with weight losses of 13.01 ± 0.08% and 7.26 ± 0.23% in 11 days, respectively. At pH 11, a sustained degradation that is almost linear degradation with time was observed for up to 30 days, with a total weight loss of 21.42 ± 0.88%. Furthermore, p(DA) particles were tested for cell toxicity against COS-1 cells and found non-toxic up to 50 µg/mL with 95.6 ± 4.5% cell viability as compared to 37.5 ± 0.03% for DA molecules. The p(DA) particles and DA were also compared for their ability to inhibit α-glucosidase; both inhibited α-glucosidase inhibition activity a concentration-dependent fashion: at concentrations of 500-4000 µg/mL, p(DA) provided 8.52-27.67% inhibition while DA inhibited 42.8-67.7% over the same concentration range. Furthermore, p(DA) particles were found to be blood compatible e.g., non-hemolytic with 1.87 ± 0.97% hemolysis ratio up to 50 µg/mL concentration and with 86.7% blood clotting index. Interestingly, p(DA) particle can be considered as an effective antioxidant with 33.5 ± 3.9 µg/ mL total phenol content in terms of gallic acid equivalency and 0.89 ± 0. 30 µmol/g trolox equivalent antioxidant capacity (TEAC). Finally, p(DA) particles and their modified forms, m-p(DA)-CSA, and m-p(DA)-CHPACl, were shown to be useful as active agent/drug delivery devices by using acyclovir as a model drug that can be readily loaded into particles and released at longer times at higher amounts for the modified p(DA) particles at physiological conditions.

Can PEI microgels become biocompatible upon betainization?

Polyethylene imine (PEI) microgels prepared via micro emulsion polymerization technique were treated with 1,3-propane sultone to obtained betainized PEI (b-PEI) microgels. The betainization reaction generated zwitterions on PEI microgel that are positive charges from quarternized amine groups of PEI, and the newly formed negative charges from SO3- groups from the modifying agent, 1,3-propane sultone offered interesting properties. The smaller size of b-PEI microgels that are obtained by simple filtration were increased with betainization from 512±14 to 1114±86nm. Also, the betainization of PEI microgel provided negative zeta potential values at high pH values as 9, 10, 11, and 12. Moreover, the b-PEI microgels render more effective dye absorption capabilities for anionic or cationic organic dyes such as Methyl Orange (MO) and Methylene Blue (MB) separately with the significant increase dye adsorption capacity of 354±31 and 274±19mg/g respectively. Moreover, antibacterial properties of b-PEI microgels tested on the E. coli ATCC 8739 and S. aureus ATCC 6538 were diminished whereas bare PEI has low MIC and MBC values (strong antibacterial properties). Interestingly, the PEI microgels known for their strong antibacterial and toxic nature found to be biocompatible upon betainization reaction. The biocompatibility test were carried with WST-1 tests and double staining methods. The cytotoxicity, apoptotic and necrotic cell tests were shown that PEI microgels induce no cytotoxicity up to 400µg/mL whereas PEI microgels possessed 50% toxicity at this concentration, suggesting that b-PEI microgels become biocompatible upon betainization with, 3-propane sultone.

P(TA) macro-, micro-, nanoparticle-embedded super porous p(HEMA) cryogels as wound dressing material.

Super porous poly(2-hydroxy ethyl methacrylate) (p(HEMA)) cryogel was successfully synthesized by using polyethylene glycol diacrylate (p(EGDA)) crosslinker under cryogenic conditions. Poly(Tannic acid) (p(TA)) macro-, micro-, and nanoparticles prepared from a natural polyphenol, tannic acid (TA), were embedded into p(HEMA) cryogel networks to obtain composite p(TA) particle-embedded p(HEMA) cryogel. Different size ranges of spherical p(TA) particles, 2000-500µm, 500-200µm, 200-20µm, and 20-0.5µm size, were included in the cryogel network and illustrated by digital camera, optic microscope, and SEM images of the microgel-cryogel network. The swelling properties and moisture content of p(TA) microgel-embedded p(HEMA) cryogel were investigated at wound healing pH conditions such as pH5.4, 7.4, and 9 at 37.5°C, and the highest swelling capacity was found at pH9 with 972±2% swelling in 30s. Higher amounts of DI water were quickly absorbed by p(HEMA)-based cryogel, and moisture retention within the cryogel structure for a longer time period at room temperature is due to existence of p(TA) particles. Degradation profiles of p(TA) particle-embedded p(HEMA) cryogel were shown to be controlled by different pH conditions, and a linear release profile was found with total cumulative release of 5.8±0.8mg/g TA up to 12days at pH7.4 and 37.5°C. The antioxidant behavior of degraded p(TA) particles from p(HEMA) cryogel were found as 46±1µgmL-1 gallic acid equivalent and 165±18mMtroloxequivalentg-1. The p(TA) particle-embedded p(HEMA) cryogel has high hemocompatibility with 0.0158±0.0126% hemolysis ratio, and effective hemostatic properties with 8.1±0.9 blood clotting index.

Polyethyleneimine modified poly(Hyaluronic acid) particles with controllable antimicrobial and anticancer effects.

Poly(hyaluronic acid) (p(HA)) particles with sizes from few hundred nm to few tens of micrometer were synthesized by using epoxy groups containing crosslinker glycerol diglycidyl ether (GDE) with high yield, 94±5%. P(HA) particles were oxidized by treatment with sodium periodate and then reacted with cationic polyethyleneimine (PEI) at 1:0.5, 1:1, and 1:2 wt ratio of p(HA):PEI to obtain p(HA)-PEI particles. From zeta potential measurements, isoelectronic points of bare p(HA) particles increased to pH 8.7 from 2.7 after modification with cationic PEI. New properties, such as antibacterial property, were attained for p(HA)-PEI after modification. The highest minimum bactericidal concentration (MBC) values were 0.5, 1, and 0.5mg/mL against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis species for 1:0.5 ratio of p(HA)-PEI at 72h incubation time. Moreover, the p(HA)-PEI particles were found to be biocompatible with L929 fibroblast cells, and interestingly, p(HA)-PEI particles were found to inhibit MDA-MB-231 breast and H1299 cancer cell growth depending on amount of PEI in p(HA)-PEI particles.

Controlled release from a nanocarrier entrapped within a microcarrier.

This study illustrates the entrapment of the dye molecule fluorescein sodium salt (FSS) by hydrogel nanoparticles, which are in turn confined inside a water-in-oil-in-water double-emulsion globule, and its subsequent release by the action of the competing agent hydrochloric acid (HCl). Thus, a "double carrier" concept is being introduced in which a nanoscale delivery vehicle is being transported by a microscale delivery vehicle in order to simultaneously take advantage of both systems. This may facilitate storage and handling while protecting the active substance and improving its action upon application.

Glaucoma drainage devices: state of the art.

Glaucoma drainage devices (GDDs) create an alternate aqueous pathway by channeling aqueous from the anterior chamber through a long tube to an equatorial plate, inserted under the conjunctiva, which promotes bleb formation. GDDs are being used more frequently in the treatment of glaucoma, both as the primary procedure of choice and following failure of trabeculectomy operations. This article outlines the current concepts involving different GDDs, surgical techniques and a review of the current literature. In addition, the importance of the biomaterial and its implications for the success of the operation are discussed.