BSA Adsorption Research Articles

Impact of coverage and guest residue on polyproline II helix peptide antifouling

AbstractPolyproline II (PPII) peptide sequences are recognized as promising biomaterials because of their attractive antifouling properties. However, the mechanisms behind their antifouling behavior have not been fully characterized. In this work we show that PPII peptide coverage, controlled by adsorption time, significantly reduces the fouling of bovine serum albumin (BSA, a model foulant). In addition, guest residues introduced into the PPII sequence are shown to significantly impact BSA adsorption as well as human mesenchymal stem cell (hMSC) spreading. This research will help guide future PPII peptide designs for incorporation into novel biomaterials. Graphical abstract

Specific buffer effects on the formation of BSA protein corona around amino-functionalized mesoporous silica nanoparticles

The effect of buffer species on biomolecules and biomolecule-nanoparticle interactions is a phenomenon that has been either neglected, or not understood. Here, we study the formation of a BSA protein corona (PC) around amino-functionalized mesoporous silica nanoparticles (MSN-NH2) in the presence of different buffers (Tris, BES, cacodylate, phosphate, and citrate) at the same pH (7.15) and different concentrations (10, 50, and 100 mM). We find that BSA adsorption is buffer specific, with the adsorbed amount of BSA being 4.4 times higher in the presence of 100 mM Tris (184 ± 3 mg/g) than for 100 mM citrate (42 ± 2 mg/g). That is a considerable difference that cannot be explained by conventional theories. The results become clearer if the interaction energies between BSA and MSN-NH2, considering the electric double layer (EEDL) and the van der Waals (EvdW) terms, are evaluated. The buffer specific PC derives from buffer specific zeta potentials that, for MSN-NH2, are positive with Tris and negative with citrate buffers. A reversed sign of zeta potentials can be obtained by considering polarizability-dependent dispersion forces acting together with electrostatics to give the buffer specific outcome. These results are relevant not only to our understanding of the formation of the PC but may also apply to other bio- and nanosystems in biological media.

Bioinspired Dopamine and N-Oxide-Based Zwitterionic Polymer Brushes for Fouling Resistance Surfaces.

Biofouling is a great challenge for engineering material in medical-, marine-, and pharmaceutical-related applications. In this study, a novel trimethylamine N-oxide (TMAO)-analog monomer, 3-(2-methylacrylamido)-N,N-dimethylpropylamine N-oxide (MADMPAO), was synthesized and applied for the grafting of poly(MADMPAO) (pMPAO) brushes on quartz crystal microbalance (QCM) chips by the combination of bio-inspired poly-dopamine (pDA) and surface-initiated atom transfer radical polymerization technology. The result of ion adsorption exhibited that a sequential pDA and pMPAO arrangement from the chip surface had different characteristics from a simple pDA layer. Ion adsorption on pMPAO-grafted chips was greatly inhibited at low salt concentrations of 1 and 10 mmol/L due to strong surface hydration in the presence of charged N+ and O- of zwitterionic pMPAO brushes on the outer layer on the chip surface, well known as the "anti-polyelectrolyte" effect. During BSA adsorption, pMPAO grafting also led to a marked decrease in frequency shift, indicating great inhibition of protein adsorption. It was attributed to weaker BSA-pMPAO interaction. In this study, the Au@pDA-4-pMPAO chip with the highest coating concentration of DA kept stable dissipation in BSA adsorption, signifying that the chip had a good antifouling property. The research provided a novel monomer for zwitterionic polymer and demonstrated the potential of pMPAO brushes in the development and modification of antifouling materials.

Degradation of tetracycline wastewater by Fe-TiO2/Bi2MoO6/PTFE photocatalytic composite membrane

A Fe-TiO2/Bi2MoO6/PTFE photocatalytic composite membrane was innovatively fabricated for TCH wastewater treatment. It was characterized by XRD, SEM-EDS, FT-IR, BET, XPS, UV–vis, water contact angle, membrane flux, and BSA adsorption. The Fe-TiO2/Bi2MoO6 particles were securely adhered to the PTFE membrane, confirmed by repeated tests, exhibiting remarkable stability. The addition of Fe3+ and the incorporation of TiO2 increased the surface area, while the formation of the Fe-TiO2/Bi2MoO6 heterojunction facilitated the efficient separation of photogenerated electron-hole pairs. Furthermore, the doping of Fe3+ simultaneously disperses TiO2 and Bi2MoO6, enhancing their interactions. This leads to a close bonding between TiO2, Bi2MoO6, and Fe3+, further enhancing the hydrophilicity of the composite membrane. Treating TCH wastewater for 2 h with Fe-TiO2/Bi2MoO6/PTFE composite membrane under UV light achieved 87.4 % TCH removal and up to 76.1 % TOC reduction. The presence of inorganic anions (Cl−, CO32−, and NO3−) and humic acid (HA) have an inhibitory effect on the removal of TCH. The free radical trapping experiment identifies ·O2− as the primary reactive species. The E. coli colony assay shows no notable antibacterial activity in the treated effluent. LC-MS analysis reveals possible TCH degradation pathways in wastewater at different times.

Magnetic Fe‐Ni bimetallic oxide shell nanorods containing anti‐protein polymer segments for protein purification

AbstractIn this paper, BSA surface‐imprinted magnetic Fe‐Ni bimetallic oxide shell nanorods (m‐FeNi@MIPs@PCBMA) were prepared with the assistance of poly(3‐[[2‐(methacryloyloxy)ethyl]dimethylammonium] propionate (PCBMA) in connection with the surface‐imprinting technique. The Fe‐Ni bimetallic oxide shell layer nanorods (m‐FeNi) with magnetic responsiveness simplified the separation and recovery process of adsorbed materials. The controlled introduction of PCBMA facilitated the reduction of protein non‐specific adsorption. At the optimal encapsulation ratio of 1:0.75 (Wm‐FeNi@MIPs: WCBMA), m‐FeNi@MIPs@PCBMA could adsorb 122.98 ± 5.00 mg/g of BSA within 80 min, and the value of the imprinting factor (IF) was also increased from 1.68 (m‐FeNi@MIPs) to 3.95. In the mixed protein adsorption and real sample separation experiments, m‐FeNi@MIPs@PCBMA could selectively separate BSA. Meanwhile, after seven adsorption–desorption experiments, the loss of BSA adsorption by the imprinted nanorods was only 15.9%, which had good reusability. Therefore, m‐FeNi@MIPs@PCBMA has a broader application prospect in the field of protein separation and purification.

Modification of titanium implants by bioactive and antibacterial zinc gallate metal organic framework

Bone diseases like rheumatoid arthritis or osteoporosis often lead to severe bone fractures requiring artificial implants. Titanium, especially its Ti6Al4V alloy, is favored for orthopedic and dental implants due to its exceptional properties. However, titanium implants face challenges like delayed osseointegration and bacterial susceptibility. Surface functionalization techniques, including antimicrobial coatings and drug delivery systems, aim to address these issues. Metal organic frameworks (MOFs), especially bio-MOFs, offer potential for implant modification due to their large surface area and biocompatible components. Here, we developed a MOF layer on titanium implants using gallic acid and Zn2+ ions to enhance antibacterial properties and bioactivity. The obtained materials were characterized using various research techniques. Using FT-IR microscopy, it was confirmed that the MOF is evenly distributed over the entire surface of the material. The MOF layer affects the hydrophilicity of the surface and the contact angle is approximately 60°. Additionally, tests for HAp growth, BSA adsorption and antibacterial performance were conducted. Our findings suggest that the MOF layer improves implant performance and biocompatibility by inducing HAp growth, enhancing protein sorption, and inhibiting microbial growth by about 20–40 % depending on the microorganism.

Facile Preparation of β-Cyclodextrin-Modified Polysulfone Membrane for Low-Density Lipoprotein Adsorption via Dopamine Self-Assembly and Schiff Base Reaction.

A facile method for the immobilization of β-cyclodextrin on polysulfone membranes with the aim of selectively adsorbing low-density lipoprotein (LDL) was established, which is based on the self-assembly of dopamine on the membrane followed by the Schiff base reaction with mono-(6-ethanediamine-6-deoxy)-β-cyclodextrin. The surface modification processes were validated using X-ray photoelectron spectroscopy and attenuated total reflectance Fourier-transform infrared spectroscopy. Surface wettability and surface charge of the membranes were investigated through the water contact angle and zeta potential analysis. The cyclodextrin-modified polysulfone membrane (PSF-CD) showed good resistance to protein solutions, as shown by the measurement of BSA adsorption. The assessment of BSA adsorption revealed that the cyclodextrin-modified polysulfone membrane (PSF-CD) exhibited excellent resistance to protein solutions. To investigate the adsorption and desorption behaviors of the membranes in single-protein or binary-protein solutions, an enzyme-linked immunosorbent assay was employed. The results revealed that the PSF-CD possessed remarkable adsorption capacity and higher affinity for LDL in both single-protein and binary-protein solutions, rendering it a suitable material for LDL apheresis.

Micro structured Ti- scaffold decorated with Tantalum based amphiphilic assembly for improved biocompatibility, corrosion resistance and bactericidal characteristics

Fouling of body implants is inevitable as they stay in contact with body fluid of harsh ionic composition with varying pH, mixed with serum proteins and bacteria. Some alloys used as implant material comes with inherent bacterial resistant character or in other case the use of antibacterial coating is a popular measure to check the biofouling of their surfaces. But the development of bacterial resistant coating which don’t compromise the cytocompatibility of implant is still a challenging task. In this research, a novel antibacterial metallosurfactant bishexadecyltrimethylammoniumtantalum heptachloride (TaC) is synthesized to coat Ti-6Al-4V surface which provides excellent replacement to pure Tantalum which is a highly demanded implant material. For this, Ti-6Al-4V surface was acid treated to grow microstructures and porosity to help covalent bonding with TaC molecules and get durable and robust coating. The TaC coating was characterized as highly stable, hydrophilic, bioactive (assist osseointegration), antimicrobial against Gram negative (E. coli) and Gram positive (S. aureus), anti- corrosive in abiotic as well as biotic medium and compatible with fibroblast tissues. Being amphiphilic in nature, the coating interferes with serum albumin (BSA) adsorption on Ti-6Al-4V surface. Retardation in BSA adsorption due to TaC coating is evident from contact angle, XPS and electro chemical studies. The key appeal of coating is its simple fabrication technique and cost-effectiveness, moreover its chemical and structural features is such that it promotes fibroblast adhesion and viability. The coating exhibited a perfect balance to cater the antibiofouling activity and fibroblast proliferation which is biggest challenge in fabrication of biomaterials. Various results obtained from this comprehensive study may advocate the clinical applications of Ta metallosurfactant coating on biomedical alloys.

Measurement of Dilational Modulus of an Adsorbed BSA Film Using Pendant Bubble Tensiometry: From a Clean Interface to Saturation

Two open issues on the measurement of the dilational modulus (E) for an adsorbed protein film during the adsorption process have been unacknowledged: how E varies during the adsorption and the length of time needed to attain a stable E value. A new approach for detecting the E variation from a clean air–water interface to saturated film and estimating the time needed to reach a saturated state was proposed. A pendant bubble tensiometer was utilized for measuring the relaxations of surface tension (ST) and surface area (SA), and the E was evaluated from the relaxation data of minute distinct perturbances. The data showed a clear variation in E during the BSA adsorption: E sharply decreased to a minimum at the early stage of BSA adsorption; then, it rose from this minimum and oscillated for a while before reaching an E corresponding to a saturated BSA film after a significant duration. The adsorbed BSA film took ~35 h to reach its saturated state, which was much longer than the reported lifetime of the adsorbed film in the literature. A rapid surface perturbation (forced bubble expansion/compression) could change the E, causing a significant drop in E followed by a slow increase to the original stable value.

TiO2-PAA-SiO2 pearl chain blend modified polyvinylidene fluoride ultrafiltration membrane with excellent oil-water separation, anti fouling performance and durability

ABSTRACT In this work, a new type of composite nanoparticles, ‘pearl chain’, was developed by linking titanium dioxide and silicon dioxide by polyacrylic acid polymer chains, and the prepared TiO2-PAA-SiO2 composite nanoparticles were analysed by SEM, Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy and thermogravimetric analysis, zeta potential, x-ray diffraction, etc. The success of this work was verified by the successful linking of TiO2-PAA-SiO2 composite nanoparticles.TiO2-PAA-SiO2 composite nanoparticles were analysed to verify the successful attachment of pearl chains. The obtained TiO2-PAA-SiO2 were subsequently blended in different ratios to prepare polyvinylidene fluoride (PVDF) ultrafiltration membranes. The membrane performance was tested by porosity and water contact angle measurements, scanning electron microscopy, as well as experiments using bovine serum proteins and MTBE interception. The results showed that when a certain amount of TiO2-PAA-SiO2 was added, the surface wettability, porosity and permeability of the prepared modified composite membranes were significantly improved, and the BSA adsorption rate was increased from 71.59% to 80.86%, and the retention rate of MTBE was increased by 77%, in addition to showing a better anti-pollution effect (FRR: 91.07%). It was finally concluded that the prepared membranes embedded with 1.0 wt.% TiO2-PAA-SiO2 nanofillers showed good overall filtration performance, better contamination resistance and remarkable durability. The present work successfully demonstrated the feasibility of using polyacrylic acid chemical chains to connect nanoparticles with different functions to prevent particle loss and substantially enhance membrane performance, which is valuable for bridging connection of composite nanoparticles and exploring the development of high-performance ultrafiltration membranes.

Design of a Facile Antifouling Sensor Based on the Synergy between an Antibody and Phase-Transited BSA.

Nonspecific adsorption has always been a critical challenge for sensor detection; thus, an efficient and facile approach for fabricating antifouling sensors is highly desirable. Here, we developed an antifouling coating on sensor surfaces, conveniently made with a simple drip of phase-transited BSA (PTB) followed by a modification with a peanut allergen antibody, which unexpectedly provides synergistic antifouling properties in sensors. Atomic force microscopy and scanning electron microscopy were used to evaluate the surface evenness. Optimizations in terms of PTB modification time and concentrations were performed using surface plasmon resonance by measuring protein resistance capabilities. Compared to bare Au surfaces, the PTB-modified surfaces exhibited low adsorption against BSA (<10 ng/cm2) and good resistance against lysozyme (Lyz). After immobilizing antibodies, the antifouling performance of the sensor coatings had an obvious enhancement, with almost no BSA adsorption and low lysozyme adsorption. The target recognition was also analyzed to verify the good sensing performance of the antifouling sensor. This understanding of antibody synergy provides suggestions for the development of antifouling sensors.

Amphoteric polyelectrolyte ultrafiltration membranes with high permeability property via in-situ modified by PES-N and PES-COOH

Ultrafiltration membrane is one of the most commonly used separation materials for wastewater treatment, due to its low operating pressure, high flux and large specific surface area. In this work, we utilized PES polymer as a polymer precursor to prepare a series of amphoteric polyelectrolyte membrane with different content of amphoteric polyelectrolyte group via simple polymer blending processes. The amphoteric polyelectrolyte groups in amphoteric polyelectrolyte membrane could effectively regulate the retention ability and significantly improve the water flux of membrane. The amphoteric polyelectrolyte membrane with the content ratio of 4:6 (PES-N/PES-COOH) exhibited the highest water flux of 467 Lm−2 h−1 and BSA retention factor of 94.2% than that of other ultrafiltration membranes owning to the abundant porosity and suitable thickness of the top layer. Moreover, the results of static BSA adsorption and flux recovery ratio also proved that the amphoteric polyelectrolyte membrane have a good BSA rejection and antifouling performance. Therefore, these results reveal a simple synthesis and design strategy for constructing the high-performance amphoteric polyelectrolyte membrane for water treatment and provide theoretical and technical guidance for water treatment process based on membrane technology.

Zwitterionic carbon quantum dots incorporated ultrafiltration membrane for efficient removal of copper ion

Copper, prized for its excellent thermal and electrical conductivity, poses risks when present in wastewater. Treating copper ion-containing wastewater is vital for human and environmental safety. Membrane separation technology offers an eco-friendly and energy-efficient solution. In this study, a mixture of cellulose acetate (CA) and thermoplastic polyurethane (TPU) was used to fabricate the tubular membrane, with quantum dots (QDs) added. Three types of QDs were introduced into the tubular membrane: carbon quantum dots (CQDs), tertiary amine CQDs (TQDs), and zwitterionic CQDs (ZQDs). At pH = 10, copper ions were chelated with sodium dimethyldithiocarbamate (SDDC) at a ratio of SDDC/Cu2+=10 (w/w), signifying a molar concentration (mol.L-1) ratio of SDDC:Cu2+=3:16. This process achieved a 99.8% removal rate of copper ion. The ZQDs-M exhibited high pure water flux of 6,227.4 L.m−2.h−1.bar−1 and 95.4% copper ion-complex rejection rate. The ZQDs-M also demonstrated excellent anti-adhesion properties, with only 4.55% relative fluorescence intensity of E. coli and 34.58% BSA adsorption. The BSA dynamic anti-fouling property of the ZQDs-M was also superior to that of tubular membrane without QDs addition.

Tyramine Adsorption Using the Modification of Takari Natural Sand-Based Silica with Bovine Serum Albumin (BSA)

In this article, we use a batch method to convey tyramine adsorption by modifying Takari natural sand-based silica with BSA and tyramine adsorption. The research stages include the optimization of adsorbent mass, pH, temperature, determination of the isotherm model, and thermodynamic parameters of tyramine adsorption. The tyramine concentration was determined using UV-Vis. The characterizations carried out were functional groups using FT-IR and surface morphology using SEM. The results of FT-IR characterization demonstrated the success of BSA modification, as observed in the C-H, N-H, and C-N groups, which are the typical functional groups of BSA. The SEM image of SiO2@BSA before tyramine adsorption revealed unevenly sized particles, uneven distribution, and agglomeration, leading to larger particles. The morphology of SiO2@BSA-tyramine appeared to be more uniform, exhibiting a smoother shape with a slightly uneven surface. The optimum pH was 5 (qe=11.74 mg/g), and the optimum temperature was 303 K (qe= 2.47 mg/g). The isotherm study showed that the adsorption adhered to the Redlich-Peterson isotherm model with an R2 value of 0.987 (qe=5.157 mg/g and n =3.759). The thermodynamic study demonstrated ∆Ho = 49.08 kJ/mol, ∆Go =-17.84; -20.05 and -22.26 kJ/mol, and ∆So =0.22 kJ/mol.K. These results indicated that the tyramine adsorption process on SiO2@BSA adsorbent occurred endothermically and spontaneously at the temperature of 303 K, and the adsorption was of a physical-chemical adsorption type.

Titanium modification using bioactive titanate layer with divalent ions and coordinated ciprofloxacin – Assessment of drug distribution using FT-IR imaging

The paper presents a new method of titanium alloy (Ti6Al4V) modification using bioactive titanate layers containing various divalent ions (Ca2+, Mg2+, Sr2+, Zn2+) and surface-coordinated ciprofloxacin. Due to the coordination of ciprofloxacin (antibiotic) on the surface of the alloy, it has great application potential. In the paper, the influence of a given cation on the effectiveness of drug sorption was determined. The most effective cation was zinc and the least effective was calcium. The distribution of the antibiotic on the alloy surface was determined using FT-IR imaging. The antibiotic was evenly distributed on alloys modified with magnesium, strontium and zinc titanates. In the case of calcium titanate, the analysis could not be performed because the amount of the drug was too small. The release profiles of ciprofloxacin indicate that it can be released for as long as 3 h for strontium and zinc titanates. The biocompatibility of the obtained materials is indicated by the results of the BSA adsorption, and HA growth test. The obtained results confirm that the proposed modification can be used in the modification of titanium implants. The big advantage of this layer is that ciprofloxacin is coordinated on the surface of the material and thus will not be removed during the surgical procedure. The creation of this type of layer may in the future allow for fewer perioperative infections, and thus fewer complications.

The Surface of a PMP Hollow Fiber Membrane Was Modified with a Diamond-like Carbon Film to Enhance the Blood Compatibility of an Artificial Lung Membrane.

The contact between the blood and the surface of medical materials causes a series of rejection reactions. In this process, the plasma protein is adsorbed to the surface of materials within seconds and binds to glycoprotein receptors on platelets, causing platelet activation, coagulation cascade, and complement activation to form thrombus, which greatly limits the application of medical materials. In our work, the surface of poly(4-methyl-1-pentene) hollow fiber membranes (PMP HFMs) was coated with a diamond-like carbon (DLC) film by the ion plating method. The blood compatibility of the DLC coating was evaluated by protein adsorption, platelet adhesion, clotting time, red blood cell (RBCs) hemolysis, dynamic coagulation, and extracorporeal blood circulation tests. Compared with the unmodified PMP membrane, the DLC film could effectively reduce protein adsorption and platelet adhesion and prolong the coagulation time. The DLC coating showed BSA adsorption of as low as 0.53 μg/cm2 as well as a long activated partial thromboplastin time (APTT) value of 71.84 s. Furthermore, the PMP membrane modified with the DLC coating was used for extracorporeal blood circulation without thrombosis forming within 28 days. The DLC coating is one of the most promising medical coatings as an artificial lung membrane in extracorporeal membrane oxygenation (ECMO) equipment.

The establishment of self-healing polyethersulfone ultrafiltration membrane by host-guest interaction between the cucurbit[8]uril and objects

Damage to ultrafiltration membrane during cleaning and the running of the process is known to lead to adverse loss of membrane integrity. Membranes with self-healing property will contribute to solve this problem, bypassing the need for real-time membrane integrity monitoring and replacing membrane frequently. Therefore, this study established the surface modified self-healing ultrafiltration membrane by interaction through cucurbit[8]uril (CB[8]) subject and objects. CB[8], PVA-MV and P(DMAEMA-r-NpMA) were employed as self-healing polymers to construct a self-healing layer on PES membrane surface through schiff base reaction and host-guest interaction. The comparison of permeability before and after membrane damage proved the effectiveness of membrane self-healing property. Furthermore, carbonyl groups with negative charge on CB[8] port and the hydrophilic groups in two guests gave the membrane hydrophilicity after that promoted the anti-pollution property of the membrane. The obtained membrane also showed excellent hydrophilicity, permeability and anti-pollution property, for example, the pure water flux of MPES-CB[8]0.15 reached to 1800.2 L/m2h, while BSA rejection rate could also be maintained at 89 %. The self-healing membrane MPES-CB[8]0.15 displayed a better FRR (89.1 %) compared with pure PES membrane, and the decrease of Rir (19.4 %) of MPES-CB[8]0.15 indicated that the adsorption of BSA was avoided. In a word, the self-healing membrane could not only solve the problem of loss of membrane integrity, but also improve comprehensive performance of membrane, such as hydrophilicity, permeability, thermal stability and mechanical properties.

Fabrication and Study of Dextran/Sulfonated Polysulfone Blend Membranes for Low-Density Lipoprotein Adsorption.

The abnormal increase in low-density lipoprotein (LDL) in human blood is a main independent risk factor for the pathogenesis of atherosclerosis, whereas a reduced LDL level effectively lowers morbidity. It is important to develop LDL adsorption materials with high efficiency and selectivity, as well as to simplify their fabrication processes. In this paper, polysulfone (PSF), sulfonated polysulfone (SPSF), and sulfonated polysulfone/dextran (SPSF/GLU) membranes were successfully fabricated for LDL adsorption using a solution casting technique. Attenuated total reflectance Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy measurements confirmed the success of the preparation. The water contact angle decreased from 89.7 ± 3.4° (PSF) to 76.4 ± 3.2° (SPSF) and to 71.2 ± 1.9° (SPSF/GLU), respectively. BSA adsorption testing showed that the SPSF/GLU with surface enrichment of sulfonate groups and glycosyl groups possessed higher resistance to protein solution. The adsorption and desorption behaviors of the studied samples in single-protein or binary-protein solutions were systematically investigated by enzyme-linked immunosorbent assay (ELISA), The results showed that SPSF/GLU, which had excellent resistance to protein adsorption, possessed a similar adsorption capacity to that of PSF. SPSF membrane exhibited excellent selective affinity for LDL in single and binary protein solutions, suggesting potential applications in LDL removal.

Tuning the surface ordering of different charged surfactants for the controlled fabrication of monetite calcium phosphate via microwave synthesis process

Morphological aspects of the material exhibits a crucial role in the physiochemical and surface properties of calcium phosphate-based nanostructures. Monetite (CaHPO4), a type of calcium phosphate is one of such material having considerable challenges associated in fabricating defined size and shape. In this study, the search for innovative and economic protocols to fabricate monetite calcium phosphate with differently charged surfactants were employed to investigate the mechanism of morphological variation through microwave assisted technique. It is found that there is significant differences in terms of morphology, size and surface charge of surfactant added monetite. The surfactant-assisted nanostructures were characterised using the X-ray diffraction technique, confirming the formation of calcium phosphate's monetite phase (CaHPO4) with a triclinic crystal system. The crystallite size was found to be 31 nm for pristine and less than 25 nm for surfactant-assisted monetite. Field emission scanning electron microscope analysis reveals the pristine has agglomerated layered formation of monetite, whereas EM (EDTA-Monetite), CM (CTAB-Monetite), and PM (Pluronic F-127-Monetite) portray flower-like petals, hexadentate bricks and bow-knot shape respectively. Furthermore, the biocompatibility of surfactant-assisted monetite particles was assessed with in-vitro protein adsorption studies, which elucidate EM and PM has greater than 600 µg of BSA adsorption rates. But in the case of lysozyme adsorption studies pristine, CM and PM shows more than 800 µg of adsorption owing to the difference in affinity of surface charges in surfactant assisted monetite. The confocal images confirm the presence of dominant live cells in surfactant-assisted monetite.

Design and characterization of dexamethasone phosphate -loaded microcapsules obtained by a double-emulsion method

Polymeric microcapsules are extensively investigated as drug delivery systems for a broad range of applications. In the present study, Dexamethasone-loaded carboxylated chitosan (CCS)/poly (vinyl alcohol) (PVA)-based microcapsules were prepared in view of their potential administration by inhalation for the treatment of lung diseases. The crosslinking between PVA and CCS was activated by [4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride] (DMT-MM) and the FTIR results proved the formation of ester bonds between the two polymers. The sizes of the obtained microcapsules are influenced by the ratio between the polymers but also by the concentration of the DMT-MM activator. Moreover, the amount of PVA in the system has an important influence on swelling degree, encapsulation efficiency, drug release degree, biodegradation and protein adsorption. The sample with the highest amount of PVA has the highest crosslinking density and thus the lowest swelling degree and encapsulation efficiency. However, an encapsulation degree of 61.3% was obtained for the sample MCP-6 with the lowest PVA content. The same sample showed the lowest BSA adsorption. A controlled and sustained Dexamethasone release of around 90% was observed in PBS at pH 7.4 and 37 °C during 24 h. All the obtained samples were hemocompatibles and thus can be used as efficient drug delivery systems.