Release Of Cefazolin Research Articles

Smart wireless flexible bandage containing drug loaded polycaprolactone microparticles for real-time monitoring and treatment of chronic wounds.

The quality of life is negatively impacted by chronic wounds for more than 25 million people in the US. They are quite prone to infection, which may lead to the eventual loss of a limb. By exposing the ulcers to treatment agents at the appropriate time, the healing rate is increased. On-demand drug release in a closed-loop system will aid us in reaching our goal. In this study, we have developed a platform capable of real-time diagnosis of bacterial infection by wirelessly reading wound pH, as well as slow and on-demand local administration of antibiotics. The drug carrier microparticles, an electrical patch, a thermoresponsive hydrogel with an integrated microheater, and a flexible pH sensor comprised the closed-loop patch. Here it is reported that slow and smart release of cefazolin can be addressed by incorporation of drug encapsulated hydrophobic microparticles embedded into a thermo-responsive hydrogel. The utilization of a programmable bandage to provide antibiotic medication highlights the need of not only choosing appropriate therapeutic substances but also the controlled release of the medicine and its rate of release within the wound area. The results of our study indicate that the use of cefazolin encapsulated polycaprolactone (PCL) microparticles can effectively regulate the application of antibiotic treatment for chronic skin wounds. The results also showed a substantial gradual release of cefazolin from the thermo-responsive Pnipam hydrogel when the wound dressing was subjected to a temperature of 37°C. We believe that the developed flexible smart bandage can have a significant impact on chronic wound healing.

Preparation of bi-layer composite films for controlled cefazolin delivery and enhanced antibacterial activity

In the present study, a wide-spectrum antibiotic drug, cefazolin was loaded into novel bi-layer composite films based on chitosan and alginate. The objective was to achieve sustained antibacterial activity at the application site, while enhancing the local efficacy of cefazolin. The physical properties of the composite films were characterized using techniques including FTIR, XRD, and SEM. Additionally, drug content uniformity, contact angle, weight variation, swelling index, drug release profiles, and kinetics were investigated. Antibacterial efficacy of the films was evaluated against Methicillin-resistant Staphylococcus aureus (MRSA), an important drug resistant pathogen. Multiple assays including time-kill, disk diffusion, and microbial penetration assays were employed to comprehensively assess various parameters of antibacterial action. The results demonstrated homogenous drug distribution and minimal weight variation in the films. Well-compatible film formations were shown by the SEM micrographs. Cefazolin release was sustained for 1440 min, and the release kinetics were fitted with the Korsmeyer-Peppas model. The fabricated films exhibited significant and sustained antibacterial activity against MRSA for a duration of 900 minutes, ultimately leading to complete eradication of viable bacterial populations. Taken together, novel films demonstrated good mechanical properties and hold great promise for biomedical applications, offering extended antibiotic release and sustained pathogen eradication.

Exploring the Model of Cefazolin Released from Jellyfish Gelatin-Based Hydrogels as Affected by Glutaraldehyde.

Due to its excellent biocompatibility and ease of biodegradation, jellyfish gelatin has gained attention as a hydrogel. However, hydrogel produced from jellyfish gelatin has not yet been sufficiently characterized. Therefore, this research aims to produce a jellyfish gelatin-based hydrogel. The gelatin produced from desalted jellyfish by-products varied with the part of the specimen and extraction time. Hydrogels with gelatin: glutaraldehyde ratios of 10:0.25, 10:0.50, and 10:1.00 (v/v) were characterized, and their cefazolin release ability was determined. The optimal conditions for gelatin extraction and chosen for the development of jellyfish hydrogels (JGel) included the use of the umbrella part of desalted jellyfish by-products extracted for 24 h (WU24), which yielded the highest gel strength (460.02 g), viscosity (24.45 cP), gelling temperature (12.70 °C), and melting temperature (22.48 °C). The quantities of collagen alpha-1(XXVIII) chain A, collagen alpha-1(XXI) chain, and collagen alpha-2(IX) chain in WU24 may influence its gel properties. Increasing the glutaraldehyde content in JGel increased the gel fraction by decreasing the space between the protein chains and gel swelling, as glutaraldehyde binds with lateral amino acid residues and produces a stronger network. At 8 h, more than 80% of the cefazolin in JGel (10:0.25) was released, which was higher than that released from bovine hydrogel (52.81%) and fish hydrogel (54.04%). This research is the first report focused on the production of JGel using glutaraldehyde as a cross-linking agent.

Cefazolin Loaded Oxidized Regenerated Cellulose/Polycaprolactone Bilayered Composite for Use as Potential Antibacterial Dural Substitute.

Oxidized regenerated cellulose/polycaprolactone bilayered composite (ORC/PCL bilayered composite) was investigated for use as an antibacterial dural substitute. Cefazolin at the concentrations of 25, 50, 75 and 100 mg/mL was loaded in the ORC/PCL bilayered composite. Microstructure, density, thickness, tensile properties, cefazolin loading content, cefazolin releasing profile and antibacterial activity against S. aureus were measured. It was seen that the change in concentration of cefazolin loading affected the microstructure of the composite on the rough side, but not on the dense or smooth side. Cefazolin loaded ORC/PCL bilayered composite showed greater densities, but lower thickness, compared to those of drug unloaded composite. Tensile modulus was found to be greater and increased with increasing cefazolin loading, but tensile strength and strain at break were lower compared to the drug unloaded composite. In vitro cefazolin release in artificial cerebrospinal fluid (aCSF) consisted of initial burst release on day 1, followed by a constant small release of cefazolin. The antibacterial activity was observed to last for up to 4 days depending on the cefazolin loading. All these results suggested that ORC/PCL bilayered composite could be modified to serve as an antibiotic carrier for potential use as an antibacterial synthetic dura mater.

WPI Hydrogels with a Prolonged Drug-Release Profile for Antimicrobial Therapy.

Infectious sequelae caused by surgery are a significant problem in modern medicine due to their reduction of therapeutic effectiveness and the patients’ quality of life.Recently, new methods of local antimicrobial prophylaxis of postoperative sequelae have been actively developed. They allow high local concentrations of drugs to be achieved, increasing the antibiotic therapy’s effectiveness while reducing its side effects. We have developed and characterized antimicrobial hydrogels based on an inexpensive and biocompatible natural substance from the dairy industry—whey protein isolate—as matrices for drug delivery. The release of cefazolin from the pores of hydrogel structures directly depends on the amount of the loaded drug and occurs in a prolonged manner for three days. Simultaneously with the antibiotic release, hydrogel swelling and partial degradation occurs. The WPI hydrogels absorb solvent, doubling in size in three days and retaining cefazolin throughout the duration of the experiment. The antimicrobial activity of cefazolin-loaded WPI hydrogels against Staphylococcus aureus growth is prolonged in comparison to that of the free cefazolin. The overall cytotoxic effect of cefazolin-containing WPI hydrogels is lower than that of free antibiotics. Thus, our work shows that antimicrobial WPI hydrogels are suitable candidates for local antibiotic therapy of infectious surgical sequelae.

Cefazolin-Loaded Double-Shelled Hollow Mesoporous Silica Nanoparticles/Polycaprolactone Nanofiber Composites: A Delivery Vehicle for Regenerative Purposes.

Purpose: As important challenges in burn injuries, infections often lead to delayed and incomplete healing. Wound infections with antimicrobial-resistant bacteria are other challenges in the management of wounds. Hence, it can be critical to synthesize scaffolds that are highly potential for loading and delivering antibiotics over long periods. Methods: Double-shelled hollow mesoporous silica nanoparticles (DSH-MSNs) were synthesized and loaded with cefazolin. Cefazolin-loaded DSH-MSNs (Cef*DSH-MSNs) were incorporated into polycaprolactone (PCL) to prepare a nanofiber-mediated drug release system. Their biological properties were assessed through antibacterial activity, cell viability, and qRT-PCR. The morphology and physicochemical properties of the nanoparticles and nanofibers were also characterized. Results: The double-shelled hollow structure of DSH-MSNs demonstrated a high loading capacity of cefazolin (51%). According to in vitro findings, the Cef*DSH-MSNs embedded in polycaprolactone nanofibers (Cef*DSH-MSNs/PCL) provided a slow release for cefazolin. The release of cefazolin from Cef*DSH-MSNs/PCL nanofibers inhibited the growth of Staphylococcus aureus. The high viability rate of human adipose-derived stem cells (hADSCs) in contact with PCL and DSH-MSNs/PCL was indicative of the biocompatibility of nanofibers. Moreover, gene expression results confirmed changes in keratinocyte-related differentiation genes in hADSCs cultured on the DSH-MSNs/PCL nanofibers with the up-regulation of involucrin. Conclusion: The high drug-loading capacity of DSH-MSNs presents these nanoparticles as suitable vehicles for drug delivery. In addition, the use of Cef*DSH-MSNs/PCL can be an effective strategy for regenerative purposes.

Electrosprayed cefazolin-loaded niosomes onto electrospun chitosan nanofibrous membrane for wound healing applications.

Chronic wounds are among the most therapeutically challenging conditions, which are commonly followed by bacterial infection. The ideal approach to treat such injuries are synergistic infection therapy and skin tissue regeneration. In the recent decades, nanotechnology has played a critical role in eradicating bacterial infections by introducing several carriers developed for drug delivery. Moreover, advances in tissue engineering have resulted in new drug delivery systems that can improve the skin regeneration rate and quality. In this study, cefazolin-loaded niosomes were electrosprayed onto chitosan membrane for wound healing applications. For this purpose, niosomes were obtained by the thin-film hydration method; electrospinning was then conducted to fabricate nanofibrous mats. In vitro characterization of the scaffold was performed to evaluate the physicochemical and biological properties. Finally, in vivo studies were carried out to evaluate the potential use of the membrane for skin regeneration. In vitro results indicated the antibacterial properties of the membrane against Staphylococcus aureus (S.aureus) and Pseudomonas aeruginosa (P.aeruginosa) due to the gradual release of cefazolin from niosomes. The scaffolds also showed no cell toxicity. In vivo studies also confirmed the ability of the membrane to enhance skin regeneration by improving re-epithelialization, tissue remodeling, and angiogenesis. The current study could well show the promising role of the prepared scaffold for skin regeneration and bacterial infection elimination.

Protein-based nanoparticles synthesized at a high shear rate and optimized for drug delivery applications

This study aims to establish a method for the preparation of protein-based nanoparticles with uniform-sized nanoparticles less than 100 nm. For this, the conventional desolvation method was enhanced by applying a high shear rate. Molecular bovine serum albumin (BSA) was exploited in the modified method. The synthesis condition was optimized by the Taguchi approach. For this, an orthogonal array of L16 was used for four parameters each at four levels. Temperature, pH, agitation speed, and the volume fraction of organic solvents (ethanol/acetone) were selected as affecting parameters. The smallest size of BSA nanoparticles was obtained at pH 8, 8 °C, 66.7% (v/v) ethanol to acetone, and 7000 rpm of agitation speed (shear rate ~73304 s−1). The nanoparticles were characterized using dynamic light scattering (DLS), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). The BSA nanoparticles with the smallest size of 76 nm were used for the controlled release of cefazolin (Cef) as one of the most commonly used antibiotics for the treatment of bacterial infections. Also, the loading capacity and in vitro drug release kinetic behavior of the BSA nanoparticles were investigated. Amongst the adsorption equilibrium isotherms fitted to the experimental data, the Freundlich isotherm was the best isotherm with R2 = 0.97. The release kinetics of Cef was followed by the Korsmeyer-Peppas model (R2 = 0.99) revealing that the drug release is controlled by the non-Fickian diffusion-based mechanism along with polymer erosion. The kinetic data showed that about 99% of the drug is released within 42 h. According to the result of this study, BSA nano-formulation could be an encouraging carrier for antibiotics delivery.

Multi-step cefazolin sodium release from bioactive TiO2 nanotubes: Surface and polymer coverage effects

Bacterial implant-related infections have been pointed out as the leading cause of metal implant failure. Recently, nanotexturization of biomaterials surface associated with antibiotic loading revealed itself as a promising strategy for enhancing osseointegration while mitigating bacterial infections. However, fewer studies describe the effects of multi-step local drug delivery. This study investigates 1 mg Cefazolin Sodium (CS) release from anodic nanotextured titanium-based devices and the effect of polymer coverage with differential aqua solubility characteristics (Chitosan—CH and Carboxymethylcellulose—CM). Results show that larger inner pore diameters are related to longer drug release times on uncovered samples. The polymeric coverage decreases the release rates, highlighting the Carboxymethylcellulose boosting the Cefazolin release time by 51–77 fold. All biomaterials exhibited a low or absent hemolytic activity and considerable bacteria inactivation. In summary, 40 °C/CM-based samples present the most promising results for drug release devices.

Fabrication and characterization of mucoadhesive bioplastic patch via coaxial polylactic acid (PLA) based electrospun nanofibers with antimicrobial and wound healing application

Polylactic acid (PLA) is the second-highest consumed bioplastic in the world. PVP/PLA-PEO complex nanofibers encapsulating collagen and cefazolin dressing scaffold were fabricated using a coaxial electrospinning method to target the release of the encapsulated compounds. It was observed that in collagen doses of 10 and 20%, the speed of healing showed a significant difference with the control sample, but the dose of 40% caused a decrease in wound healing rate in mice. The nanofibers' morphology and surface roughness were investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. The mechanical properties and adhesion strength of the scaffolds were investigated. The scaffolds' antimicrobial activity was evaluated by disk diffusion method against the E. coli, S. aureus, and P. aeruginosa. The results indicated a positive effect on the antimicrobial activity of the samples. In this study, we were able to prolong the effect of scaffolds by changing the pattern of release of cefazolin from inside the nanofibers. Possible interactions between the polymers and the encapsulated compounds were investigated using Fourier-transform infrared spectroscopy (FTIR). Finally, in-vivo and histological tests were performed to evaluate the efficacy of the scaffolds in accelerating wound healing.

Formulation Development, Characterization and In Vitro Antibacterial Activity Evaluation of Cefazolin Loaded Mesoporous Silica Nanoparticles

The main aims of this manuscript are to: i) investigate the high drug loading of cefazolin and its characterization, ii), demonstrate the bioactivity of the cefazolin particles in vitro on Staphylococcus aureus. From our results, it is observed that the cefazolin loading into MCM-41 particles is 34 wt %. Furthermore, particles showed the burst release of cefazolin at pH 6.8. At higher concentration, MCM-41 particles are comparatively more cytotoxic as compared to lower concentration. Finally, cefazolin loaded particles showed higher in vitro antibacterial activity against Staphylococcus aureus as compared to cefazolin only.

Mesoporous silica pellets as bifunctional bone drug delivery system for cefazolin.

For decades, bone drug delivery systems dedicated for osteomyelitis treatment have been investigated as bifunctional materials that exhibit prolonged drug release and mineralization potential. Herein, composite-type pellets based on cefazolin-loaded amino-modified mesoporous silica SBA-15 and microwave-assisted hydroxyapatite were investigated as potential bone drug delivery system in vitro. Pellets were obtained by granulation, extrusion and spheronization methods in laboratory scale and studied in terms of physical properties, drug release, mineralization potential, antimicrobial activity and cytotoxicity towards human osteoblasts. The obtained pellets were characterized for hardness and friability which indicated the pellets durability during further investigations. Prolonged (5-day) release of cefazolin from pellets was observed. The pellets exhibited mineralization potential in simulated body fluid, i.e., a continuous layer of bone-like apatite was formed on the surface of pellets after 28days of incubation. An antimicrobial assay of pellets revealed an antibacterial effect against Staphylococcus aureus strain during 6days. No cytotoxic effects of pellets towards human osteoblasts were observed. The obtained results proved that proposed pellets appear to have potential applications as bone drug delivery systems.

Antibiotic eluting poly(ester urea) films for control of a model cardiac implantable electronic device infection

Cardiac implantable electronic device (CIED) infections acquired during or after surgical procedures are a major complication that are challenging to treat therapeutically, resulting in chronic and sometimes fatal infections. Localized delivery of antibiotics at the surgical site could be used to supplement traditional systemic administration as a preventative measure. Herein, we investigate a cefazolin-eluting l-valine poly(ester urea) (PEU) films as a model system for localized antibiotic delivery for CIEDs. Poly(1-VAL-8) PEU was used to fabricate a series of antibiotic-loaded films with varied loading concentrations (2%, 5%, 10% wt/wt) and thicknesses (40 µm, 80 µm, 140 µm). In vitro release measurements show thickness and loading concentration influence the amount and rate of cefazolin release. Group 10%-140 µm (load-thickness) showed 22.5% release of active pharmaceutical ingredient (API) in the first 24 h and 81.2% of cumulative percent release through day 14 and was found most effective in bacterial clearance in vitro. This group was also effective in clearing a bacterial infection in a model in vivo rat study while eliciting a limited inflammatory response. Our results suggest the feasibility of cefazolin-loaded PEU films as an effective sustained release matrix for localized delivery of antibiotics. Significance StatementImplant-associated infections acquired during surgical procedures are a major complication that have proven a challenge to treat clinically, resulting in chronic and sometimes fatal infections. In this manuscript, we investigate an antibiotic-eluting L-valine poly(ester urea) (PEU) films as a model system for localized delivery of cefazolin. Significantly, we demonstrate a wide variation in temporal delivery and dosing within this family of PEUs and show that the delivery can be extended by varying the film thickness. The in vivo results show efficacy in an infected wound model and suggest antibiotic loaded PEU films function as an effective sustained release matrix for localized delivery of antibiotics across a number of clinical indications.

Aminopropyl-functionalized mesoporous silica SBA-15 as drug carrier for cefazolin: adsorption profiles, release studies, and mineralization potential

Abstract In this study, the effect of 3-aminopropyl surface functionalization of ordered mesoporous silica SBA-15 on cefazolin adsorption and release profiles was investigated. The mineralization potential of functionalized SBA-15 in simulated body fluid was also investigated. The 3-aminopropyl-functionalized SBA-15 (SBA-NH2) were obtained by post-synthesis treatment of the parent SBA-15. The loading of cefazolin on SBA-NH2 was performed by using adsorption process from water solutions. The adsorption efficiency was characterized by applying the Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models. The adsorption kinetics were investigated using pseudo-first and pseudo-second order models as well as intraparticle diffusion model. It was found that the equilibrium data were best fitted by the Langmuir isotherm. Cefazolin adsorption followed the pseudo-second order kinetics. The cefazolin-loaded SBA-NH2 showed prolonged release profile for a period of 7 days. Cefazolin release was characterized by zero-order kinetics with reduced burst release. After 60 days of the mineralization studies the hydroxyapatite was formed on the cefazolin-loaded SBA-NH2 surface. This preliminary study supports the potential use of SBA-NH2 as a bifunctional drug carrier with prolonged cefazolin release and mineralization properties.

Amino-modified mesoporous silica SBA-15 as bifunctional drug delivery system for cefazolin: Release profile and mineralization potential

In this paper the amino-modified mesoporous silica (SBA-NH2) was investigated as a potential bifunctional drug delivery system for cefazolin with both prolonged drug release and mineralization properties. The primary SBA-15 was synthesized using sol-gel method and surface functionalization was carried out using post-synthesis grafting. The obtained SBA-NH2 was characterized by higher adsorption efficiency of cefazolin with drug release prolonged to 7 days compared to primary SBA-15. The amino-modified SBA-15 exhibited also mineralization potential after immersion in simulated body fluid (SBF) with delayed hydroxycarbonate apatite (HCA) formation compared to SBA-15 which did not interrupt the cefazolin release in controlled manner. A bone-mineral-mimicking layer of HCA was formed on the SBA-NH2 surface after 28 days in SBF.

3D printed Polycaprolactone scaffolds with dual macro-microporosity for applications in local delivery of antibiotics

Advanced scaffolds used in tissue regenerating applications should be designed to address clinically relevant complications such as surgical site infection associated with surgical procedures. Recognizing that patient-specific scaffolds with local drug delivery capabilities are a promising approach, we combined 3D printing with traditional salt-leaching techniques to prepare a new type of scaffold with purposely designed macro- and micro-porosity. The dual macro/micro porous scaffolds of medical-grade polycaprolactone (mPCL) were characterized for their porosity, surface area, mechanical properties and degradation. The use of these scaffolds for local prophylactic release of Cefazolin to inhibit S. aureus growth was investigated as an example of drug delivery with this versatile platform. The introduction of microporosity and increased surface area allowed for loading of the scaffold using a simple drop-loading method of this heat-labile antibiotic and resulted in significant improvement in its release for up to 3 days. The Cefazolin released from scaffolds retained its bioactivity similar to that of fresh Cefazolin. There were no cytotoxic effects in vitro against 3 T3 fibroblasts at Cefazolin concentration of up to 100 μg/ml and no apparent effects on blood clot formation on the scaffolds in vitro. This study therefore presents a novel type of scaffolds with dual macro- and micro-porosity manufactured by a versatile method of 3D printing combined with salt-leaching. These scaffolds could be useful in tissue regeneration applications where it is desirable to prevent complications using local delivery of drugs.

Controlled release of cefazolin sodium antibiotic drug from electrospun chitosan-polyethylene oxide nanofibrous Mats

Antimicrobial electrospun chitosan–polyethylene oxide (CS-PEO) nanofibrous mats containing cefazolin, fumed silica (F. silica) and cefazolin-loaded fumed silica nanoparticles (NPs) were produced for biomedical applications. The FE-SEM images revealed that the F. silica and F. silica-cefazolin NPs had average diameters of 40±10 and 60±15nm, respectively. Also, the fibers diameters were approximately 160±30, 90±20 and 70±15nm for the pure CS-PEO, CS-PEO-1% F. silica and CS-PEO-1% F. silica-0.5% cefazolin nanofibrous mats, respectively indicating addition of F. silica and cefazolin loaded F. silica NPs to the CS-PEO mat led to decreasing the nanofiber diameter. Both of the CS-PEO mats containing 2.5% cefazolin and 1% F. silica-0.50% cefazolin showed 100% bactericidal activities against both S. aureus and E. coli bacteria. The cefazolin release from mats was sharply increased within first 24 and 6hours for the CS-PEO mats including 2.5% cefazolin and 1% F. silica-0.50% cefazolin but after that the drug was released very slowly. The improved hydrophilicity, higher tensile strength and sustained drug release for CS-PEO-1% F. silica-0.50% cefazolin suggested that it was the best nanocomposite tissue/device for biomedical applications among the mats CS-PEO-2.5% cefazolin and CS-PEO-1% F. silica. The wound healing ability of the CS-PEO-F. silica-cefazolin mat was evaluated on the wounded skins of the female Wistar rats and it was shown that the wounded skins of the rats were almost entirely healed after ten days using this mat as a wound dressing scaffold.

The release of cefazolin from chitosan/polyvinyl alcohol/sepiolite nanocomposite hydrogel films

Films of chitosan/polyvinyl alcohol (PVA)/sepiolite nanocomposite were prepared by a simple and “green” route through solution mixing; followed by freezing–thawing cycles. The structures of nanocomposites were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis, X-ray diffractometry, and Fourier transform infrared spectroscopy. The SEM and TEM micrographs confirmed a needle-type dispersion of sepiolite nanoclay in the hydrogel nanocomposites. The effects of sepiolite and chitosan/PVA weight ratio on the swelling of nanocomposites were investigated. The water absorbency of nanocomposites was decreased by introducing sepiolite nanoclay. The nanocomposites with high content of chitosan showed high swelling capacity. The nanocomposite films showed pH-dependent swelling behavior with a maximum water absorbency under acidic pH. The cefazolin with a broad-spectrum activity toward gram-positive and gram-negative bacteria was loaded in hydrogels. The release of cefazolin from nanocomposites was evaluated at pH 7.4. The content of released drug was affected by both sepiolite amount and chitosan/PVA weight ratio. The nanocomposites films released more cefazolin than the neat hydrogel film. Cefazolin-loaded nanocomposites showed the antibacterial activity with a large zone of inhibition against gram-positive Bacillus cereus bacterium.

Drug release behavior of electrospun twisted yarns as implantable medical devices

In this study, twisted drug-loaded poly(L-lactide) (PLLA) and hybrid poly(L-lactide)/poly(vinyl alcohol) (PLLA/PVA) yarns were produced using an electrospinning technique based on two oppositely charged nozzles. Cefazolin, an antibiotic drug was incorporated in the yarn fibers by addition to the PLLA electrospinning solution. Morphological studies showed that independent of the twist rate, uniform and smooth fibers were formed. The diameter of the electrospun fibers in the yarns decreased at higher twist rates but produced yarns with larger diameters. At increasing twist rates the crystallinity of the fibers in the yarns increased. In the presence of cefazolin the fiber diameter, yarn diameter and crystallinity were always lower than in the non-drug loaded yarns. In addition the yarn mechanical properties revealed a slightly lower strength, modulus and elongation at break upon drug loading. The effect of the twist rate on the cefazolin in vitro release behavior from both PLLA and hybrid yarns revealed similar profiles for both types of drug-loaded yarns. However, the total amount of drug released from the hybrid PLLA/PVA yarns was significantly higher. The release kinetics over a period of 30 d were fitted to different mathematical models. Cefazolin release from electrospun PLLA yarns was governed by a diffusion mechanism and could best be fitted by Peppas and Higuchi models. The models that were found best to describe the drug release mechanism from the hybrid PLLA/PVA yarns were a first-order model and the Higuchi model.

Cefazolin-loaded mesoporous silicon microparticles show sustained bactericidal effect against Staphylococcus aureus

Cefazolin is an antibiotic frequently used in preoperative prophylaxis of orthopedic surgery and to fight secondary infections post-operatively. Although its systemic delivery in a bulk or bolus dose is usually effective, the local and controlled release can increase its effectiveness by lowering dosages, minimizing total drug exposure, abating the development of antibiotic resistance and avoiding the cytotoxic effect. A delivery system based on mesoporous silicon microparticles was developed that is capable of efficiently loading and continuously releasing cefazolin over several days. The in vitro release kinetics from mesoporous silicon microparticles with three different nanopore sizes was evaluated, and minimal inhibitory concentration of cefazolin necessary to eliminate a culture of Staphylococcus aureus was identified to be 250 µg/mL. A milder toxicity toward mesenchymal stem cells was observed from mesoporous silicon microparticles over a 7-day period. Medium pore size-loaded mesoporous silicon microparticles exhibited long-lasting bactericidal properties in a zone inhibition assay while they were able to kill all the bacteria growing in suspension cultures within 24 h. This study demonstrates that the sustained release of cefazolin from mesoporous silicon microparticles provides immediate and long-term control over bacterial growth both in suspension and adhesion while causing minimal toxicity to a population of mesenchymal stem cell. Mesoporous silicon microparticles offer significant advantageous properties for drug delivery applications in tissue engineering as it favorably extends drug bioavailability and stability, while reducing concomitant cytotoxicity to the surrounding tissues.