Preparation and In Vitro Evaluation of bFGF-Loaded Chitosan Nanoparticles

PLA tissue-engineered scaffolds loaded with sustained-release active substance chitosan nanoparticles: Modeling BSA-bFGF as the active substance

The utilization of basic fibroblast growth factor (bFGF) in the development of tissue-engineered scaffolds is both challenging and imperative. In our pursuit of creating a scaffold that aligns with the natural healing process, we initially fabricated chitosan-bFGF nanoparticles (CS-bFGF NPs) through electrostatic spraying. Subsequently, polylactic acid (PLA) fiber was prepared using electrospinning technique, and the CS-bFGF NPs were uniformly embedded within the pores of porous PLA fibers. Scanning electron micrographs illustrate the smooth surface of the nanoparticles, showing a porous structure intricately attached to PLA fibers. Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) analyses provided conclusive evidence that the CS-bFGF NPs were uniformly distributed throughout the porous PLA fibers, forming a robust physical bond through electrostatic adsorption. The resultant scaffolds exhibited commendable mechanical properties and hydrophilicity, facilitating a sustained-release for 72 h. Furthermore, the biocompatibility and degradation performance of the scaffolds were substantiated by monitoring conductivity and pH changes in pure water over different time intervals, complemented by scanning electron microscopy (SEM) observations. Cell experiments confirmed the cytocompatibility of the scaffolds. In animal studies, the group treated with 16 % NPs/Scaffold demonstrated the highest epidermal reconstruction rate. In summary, our developed materials present a promising candidate for serving as a tissue engineering scaffold, showcasing exceptional biocompatibility, sustained-release characteristics, and substantial potential for promoting epidermal regeneration.

Effect of C7-3-Peptide-Loaded Chitosan Nanoparticles Against Multi-Drug-Resistant Neisseria gonorrhoeae

Introduction

The emergence of Neisseria gonorrhoeae-resistant strains represents one of the most urgent global threats. In this regard, C7-3 peptide is one of the anti-virulence therapies that has demonstrated promising anti-gonococcal activity. Accordingly, this research aimed to formulate C7-3 peptide and its derivatives in chitosan nanoparticles.

Methods

The peptide loaded chitosan nanoparticles were prepared using ion gelation method, and their physicochemical characteristics were investigated. The anti-gonococcal and antibiofilm activity of prepared NPs was assessed, and their cytotoxicity in human ovarian cells was evaluated.

Results

All prepared NPs were optimized for the smallest particle size of 136.9 to 168.3 nm. The EE% of C7-3, C7-3m1, and C7-3m2 CNPs reached 90.2, 92.5, and 91.8%, respectively. An in vitro release study demonstrated a continuous sustained-release pattern of C7-3 peptide from NPs. The SDS-PAGE assay confirmed the integrity of C7-3 peptide after the fabrication process. When comparing each peptide alone, the generated NPs demonstrated higher anti-gonococcal and anti-biofilm effectiveness against standard and resistant bacterial strains under anaerobic conditions. The cytotoxicity experiments revealed the cytocompatibility of NPs in HeLa cell lines. Given the advantages of enhanced anti-gonococcal activity of the C7-3 peptide and its derivatives when loaded with CNPs, as well as the antimicrobial properties of chitosan NPs, the reported NPs have great potential in the treatment of gonococcal infection.

Protein-modified nanomaterials: emerging trends in skin wound healing

Prolonged inflammation can impede wound healing, which is regulated by several proteins and cytokines, including IL-4, IL-10, IL-13, and TGF-β. Concentration-dependent effects of these molecules at the target site have been investigated by researchers to develop them as wound-healing agents by regulating signaling strength. Nanotechnology has provided a promising approach to achieve tissue-targeted delivery and increased effective concentration by developing protein-functionalized nanoparticles with growth factors (EGF, IGF, FGF, PDGF, TGF-β, TNF-α, and VEGF), antidiabetic wound-healing agents (insulin), and extracellular proteins (keratin, heparin, and silk fibroin). These molecules play critical roles in promoting cell proliferation, migration, ECM production, angiogenesis, and inflammation regulation. Therefore, protein-functionalized nanoparticles have emerged as a potential strategy for improving wound healing in delayed or impaired healing cases. This review summarizes the preparation and applications of these nanoparticles for normal or diabetic wound healing and highlights their potential to enhance wound healing.

Fabrication and characterization of electrospun GelMA/PCL/CS nanofiber composites for wound dressing applications

In the present study, the effect of different ratios of GelMA concentration has been exhibited for wound dressing implementation by the electrospinning method using a new polymer combination of Gelatin methacrylate (GelMA)/Polycaprolactone (PCL)/Chitosan (CS). The nanofiber composites were fabricated due to their biocompatible, biodegradable, improved mechanical strength, low degradation rate, and hydrophilic nature to develop cell-mimicking, cell adhesion, proliferation, and differentiation. Different concentrations of GelMA were added to the PCL/CS solution as 5, 10, and 20 wt%, respectively, in the formic acid/acetic acid (7:3) solution. A photoinitiator was added to the solution for photo-crosslinking of GelMA. The influence of different solution concentrations (5, 10, and 20 wt%) on the structure’s nanofiber production and fiber morphology was examined. SEM micrographs revealed that varied GelMA concentrations resulted in suitable and stable nanofiber composites. The average diameter of nanofiber composites grows as the GelMA concentration rises. FTIR, DSC, tensile test, degradation, and swelling test were evaluated. The results demonstrated that high mechanical strength, hydrophilic properties, and a slow degradation rate were observed with the presence and increment of GelMA concentration within the nanofiber composites. The antibacterial potential of GelMA/PCL/CS nanofiber composites was evaluated against P. aeruginosa and S. aureus using a disc diffusion assay. In vitro cell culture research was conducted by seeding NIH 3T3 fibroblast cells on nanofiber composites, proving these cells’ high cell proliferation rate, viability, and adhesion. 10 wt% GelMA-based nanofiber composites were found to have great potential for wound dressing applications.

Chitosan nanoparticles encapsulated into PLA/gelatin fibers for bFGF delivery

Electrospinning is a trendy method because of the ease of use and the high surface-to-volume ratio. The mechanical and biological properties of polylactic acid (PLA) make it one of the most enticing polymers. Gelatin and PLA together are thought to enhance cellular behavior and hydrophilicity of scaffolds. Furthermore, chitosan nanoparticles (CNPs) can be incorporated into PLA fibers to achieve controlled growth factor release. This study utilized PLA–gelatin nanofibrous scaffolds in which CNPs were encapsulated within PLA fibers to achieve a controlled release of basic fibroblast growth factor (bFGF). To produce CNPs, a simple ionic gelation reaction was used. The optimal diameter of CNPs was determined by investigating chitosan to tricalciumphosphatesodium (TPP) ratio and TPP concentration. Using a spectrophotometer, we measured the release rate of bFGF from CNPS and scaffolds. Images from a scanning electron microscope (SEM) were used to assess the effect of various concentrations of PLA and gelatin on fiber diameter. The results showed that PLA–gelatin scaffolds could stimulate the release of growth factors and promote cell proliferation. Using a two-jet electrospinning device to produce PLA–gelatin fibers in combination with CNPs incorporated within PLA fibers to release the bFGF growth factor is the novelty of this study.

Superhydrophobic Surface for Enhancing the Bioavailability of Salbutamol Sulfate from Cross-Linked Microspheres: Formulation, Characterization, and in vivo Evaluation

Introduction

The aim of the work was to formulate salbutamol sulfate (SB) microspheres by using superhydrophobic surface (SHS) under different processing factors for improving its encapsulation efficiency, controling its release rate, and hence enhancing its bioavailability.

Methods

Cross-linked microspheres of chitosan (CN) and carrageenan (KN) were made on a SHS under a glutaraldehyde-saturated atmosphere. The formulations were designed and optimized based on 4² factorial design. Percentage encapsulation efficiency (%EE), particle size, swelling ratio, and in vitro release rate were characterized, and the in vivo performance of optimized formula was investigated in beagle dogs.

Results

The results showed that the prepared microspheres have a high %EE (97.11±0.78%) for F13. The swelling ratio was 4.2 at the end of the 8 hours for the optimized formula, and the in vitro release rate was controlled for 12 hours. In vivo study verified that there was a 1.61-fold enhancement in SB bioavailability from optimized formula (F13) compared to market tablet.

Conclusion

The study suggested that microspheres prepared from CN/KN crosslinking on an SHS using glutaraldehyde atmosphere is a promising technique that can encapsulate and sustain the release of water-soluble drugs such as SB in addition to improving its in vivo pharmacokinetic profile.

Nanochitosan: Commemorating the Metamorphosis of an ExoSkeletal Waste to a Versatile Nutraceutical

Chitin (poly-N-acetyl-D-glucosamine) is the second (after cellulose) most abundant organic polymer. In its deacetylated form-chitosan-becomes a very interesting material for medical use. The chitosan nano-structures whose preparation is described in this article shows unique biomedical value. The preparation of nanochitosan, as well as the most vital biomedical applications (antitumor, drug delivery and other medical uses), have been discussed in this review. The challenges confronting the progress of nanochitosan from benchtop to bedside clinical settings have been evaluated. The need for inclusion of nano aspects into chitosan research, with improvisation from nanotechnological inputs has been prescribed for breaking down the limitations. Future perspectives of nanochitosan and the challenges facing nanochitosan applications and the areas needing research focus have been highlighted.

Pharmacokinetic and pharmacodynamic studies of etodolac loaded vesicular gels on rats by transdermal delivery

BACKGROUND

The present study includes the development of liposomal and ethosomal gels for transdermal delivery to overcome the side effects associated with oral route.

METHODS

The liposomes and ethosomes were prepared by 32 factorial design using film hydration and cold methods, respectively. Different concentrations of liposomal (ETO-LG) and ethosomal (ETO-EG) gels were prepared at 1%, 2 and 3% (w/v) using carbopol 940 NF. 1%w/v ETO-LG & ETO-EG were optimized upon rheological studies of prepared gels. The optimized gels were further characterized for various physicochemical properties and biophysical studies using FTIR, pharmacokinetic (PK) and pharmacodynamic (PD) studies. The pharmacodynamic activity was performed using carrageenan paw oedema model. The prepared vesicular gels were compared with 45% v/v ethanolic ETO-solution and marketed gel PROXYM® in all the characteristic parameters.

RESULTS

The pharmacokinetic study reveals that the half life of etodolac in ETO-EG was 1.56 folds whereas ETO-LG showed 1.31 folds higher than PROXYM®. The mean residence time (MRT) of etodolac in ETO-EG and ETO-LG is increased in 1.57 and 1.25 folds, respectively, when compared to PROXYM®. The ETO-EG showed higher percentage reduction in oedema (81.67%) compared to other test products.

CONCLUSION

The pharmacokinetic and pharmacodynamic studies indicated that the vesicular gels show better results compared to PROXYM®. The correlation coefficient value between PK and PD was found to be 0.9635. Graphical abstract ᅟ.

Preparation of NGF encapsulated chitosan nanoparticles and its evaluation on neuronal differentiation potentiality of canine mesenchymal stem cells

Sustained and controlled release of neurotrophic factors in target tissue through nanomaterial based delivery system could be a better strategy for nerve tissue regeneration. The present study aims to prepare the nerve growth factor (NGF) encapsulated chitosan nanoparticles (NGF-CNPs) and its evaluation on neuronal differentiation potentiality of canine bone marrow derived mesenchymal stem cells (cBM-MSCs). The NGF-CNPs were prepared by ionotropic gelation method with tripolyphosphate (TPP) as an ionic cross-linking agent. Observations on physiochemical properties displayed the size of nanoparticles as 80-90 nm with positive zeta potential as well as an ionic interaction between NGF and nanoparticle. NGF loading efficiency was found to be 61% while its sustained release was observed by an in vitro release kinetics study. These nanoparticles were found to be cytocompatible to cBM-MSCs when supplemented at a concentration upto 4 mg/ml in culture media. The NGF-CNP supplemented culture media was able to transdifferentiate the preinduced cBM-MSCs into neurons in a better way than unbound NGF supplementation. Further, it was also noticed that NGF-CNPs were able to transdifferentiate cBM-MSCs without any chemical based preinduction. In conclusion, our findings propose that NGF-CNPs are capable of releasing bioactive NGF with the ability to transdifferentiate mesenchymal stem cells into neurons, suggesting its potential future application in nerve tissue regeneration.

Antibacterial and anti-inflammatory drug delivery properties on cotton fabric using betamethasone-loaded mesoporous silica particles stabilized with chitosan and silicone softener

In this study, mesoporous silica particles with a hexagonal structure (SBA-15) were synthesized and modified with (3-aminopropyl) triethoxysilane, and used as a carrier for anti-inflammatory drug, betamethasone sodium phosphate. Drug-loaded silica particles were grafted on the cotton fabric surface using chitosan and polysiloxane reactive softener as a soft and safe fixing agent to develop an antibacterial cotton fabric with drug delivery properties. Cytometry assays revealed that synthesized silica have no cytotoxicity against human peripheral blood mononuclear cells. Accordingly, the produced drug-loaded nanostructures can be applied via different routes, such as wound dressing. Drug delivery profile of the treated fabrics were investigated and compared. The drug release rate followed the conventional Higuchi model. The treated cotton fabrics were tested and evaluated using scanning electron microscope images, bending length, air permeability, washing durability and anti-bacterial properties. It was found that the chitosan-/softener-treated fabrics compounded with drug-loaded silica particles have a good drug delivery performance and exhibited a powerful antibacterial activity against both Escherichia coli and Staphylococcus aureus even after five washing cycles. The produced antibacterial cotton fabric with drug delivery properties could be proposed as a suitable material for many medical and hygienic applications.

Preparation of alginate-chitosan fibers with potential biomedical applications

The preparation of alginate-chitosan fibers, through wet spinning technique, as well as the study of their properties as a function of chitosan's molecular weight and retention time in the coagulation bath, is presented and discussed in this work. Scanning electron microscopy (SEM) revealed that the fibers presented irregular and rough surfaces, with a grooved and heavily striated morphology distributed throughout the structure. Dynamic mechanical analysis (DMA) showed that, with the exception of elongation at break, the incorporation of chitosan into the fibers improved their tensile properties. The in vitro release profile of sulfathiazole as a function of chitosan's molecular weight indicated that the fibers are viable carriers of drugs. Kinetic models showed that the release of the model drug is first-order, and the release mechanism is governed by the Korsmeyer-Peppas model. Likewise, fibers loaded with sulfathiazole showed excellent inhibition of Escherichia coli growth after an incubation time of 24h at 37 °C.

Advances in chitosan-based drug delivery vehicles

Within the past few years, chitosan-based drug delivery vehicles have become some of the most attractive to be studied. In contrast to all other polysaccharides, chitosan has demonstrated its unique characteristics for drug delivery platforms, including its active primary amino groups for chemical modification, simple and mild preparation methods for the encapsulation of biomolecules or drugs, mucoadhesion to facilitate transport across mucosal barriers and so on. In this review, an overview of the various types of chitosan-based drug delivery systems is provided, with special focus on polymeric drug conjugates and drug nanocarriers. The first part of the review is concerned with the development and applications of polymeric chitosan-drug conjugates. Then the chitosan-based nanocarrier systems as well as their preparation methods and applications are further discussed.

In vitro evaluation of dual growth factor-incorporated chitosan nanoparticle impregnated collagen–chitosan scaffold for tissue engineering

Artificial tissue constructs require vehicles for controlled release of growth factor to induce cellular signaling in vivo conditions. The objective of this study was to develop a three-dimensional porous tissue engineering scaffold with the capability of carrying nanoparticles for their controlled release. Epidermal growth factor and fibroblast growth factor were encapsulated into chitosan nanoparticles of an average diameter of 50–100 nm. Porous collagen–chitosan scaffolds were prepared by freeze-drying method. The pores of the scaffolds were well interconnected, with a mean diameter of 75–150 µm. The in vitro release kinetics data indicated that nanoparticle impregnated scaffolds released epidermal growth factor and fibroblast growth factor in a sustainable manner. The cytocompatibility, proliferation, and cell attachment characteristics of the biopolymeric scaffolds were evaluated through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, flow cytometry, and scanning electron microscope. The results demonstrated that the dual delivery of epidermal growth factor and fibroblast growth factor from chitosan nanoparticles of collagen–chitosan scaffolds significantly enhanced the cellular viability and activity. The in vitro data clearly confirmed that the growth factors incorporated in chitosan nanoparticles and placed in hybrid scaffolds have favorable characteristics for drug delivery and tissue engineering application.

A fibrin gel loaded with chitosan nanoparticles for local delivery of rhEGF: preparation and in vitro release studies

Recombinant human epidermal growth factor (rhEGF) is known to stimulate cell proliferation and accelerate wound healing. Direct delivery of rhEGF at the wound site in a sustained and controllable way without loss of bioactivity would enhance its biological effects. The aim of this study was to prepare a novel local delivery system for the sustained and controllable release of rhEGF, a fibrin gel loaded with chitosan nanoparticles. First, rhEGF-loaded chitosan nanoparticles were prepared and characterized, and these showed an ability to protect rhEGF from proteolysis. The prepared nanoparticles were then incorporated into a fibrin gel matrix during polymerization. In vitro release studies showed that the fibrin gel loaded with rhEGF/chitosan nanoparticles could achieve a more sustained release of rhEGF than either chitosan nanoparticles or an unloaded fibrin gel. Additionally, the release rate could be controlled by altering the contents of fibrinogen and thrombin in this composite delivery system. The bioactivity of the released rhEGF was determined by assessing its ability to stimulate the proliferation of BALB/c 3T3 cells, and the results showed that rhEGF bioactivity was not affected during the preparation process and could be maintained for at least 7 days. This novel delivery system may have great potential applications in the local administration of rhEGF.

Chitosan nanoparticles: a promising system in novel drug delivery

The ability of nanoparticles to manipulate the molecules and their structures has revolutionized the conventional drug delivery system. The chitosan nanoparticles, because of their biodegradability, biocompatibility, better stability, low toxicity, simple and mild preparation methods, offer a valuable tool to novel drug delivery systems in the present scenario. Besides ionotropic gelation method, other methods such as microemulsion method, emulsification solvent diffusion method, polyelectrolyte complex method, emulsification cross-linking method, complex coacervation method and solvent evaporation method are also in use. The chitosan nanoparticles have also been reported to have key applications in parentral drug delivery, per-oral administration of drugs, in non-viral gene delivery, in vaccine delivery, in ocular drug delivery, in electrodeposition, in brain targeting drug delivery, in stability improvement, in mucosal drug delivery in controlled drug delivery of drugs, in tissue engineering and in the effective delivery of insulin. The present review describes origin and properties of chitosan and its nanoparticles along with the different methods of its preparation and the various areas of novel drug delivery where it has got its application.

Hyaluronic acid/Chitosan nanoparticles as delivery vehicles for VEGF and PDGF-BB

The development of a vascular network in tissue-engineered constructs is a fundamental bottleneck of bioregenerative medicine, particularly when the size of the implant exceeds a certain limit given by diffusion lengths and/or if the host tissue shows a very active metabolism. One of the approaches to achieve the vascularization of tissue constructs is generating a sustained release of proangiogenic factors from the ischemic site. This work describes the formation and characterization of hyaluronic acid-chitosan (HA/CS) nanoparticles for the delivery of two pro-angiogenic growth factors: vascular endothelial growth factor (VEGF) and platelet derived growth factor (PDGF-BB). These nanoparticles were prepared by an ionic gelification technique, and different formulations were developed by encapsulating the growth factors in association with two stabilizing agents: bovine serum albumin or heparin sodium salt. These carriers were characterized with regard to their physicochemical properties, their stability in biological media, and their cytotoxicity in the C3a hepatoma cell line. The results show that nanoparticles around 200 nm can be prepared by this method. HA/CS nanoparticles were stable when incubated in EMEM cell culture medium or in water at 37°C for 24 h. Cell culture tests confirmed that HA/CS nanoparticles are not cytotoxic within the concentration range used for growth factor delivery. Moreover, HA/CS nanoparticles were able to entrap efficiently both growth factors, reaching association values of 94% and 54% for VEGF and PDGF, respectively. In vitro release studies confirm that PDGF-BB is released from HA/CS nanoparticles in a sustained manner over approximately 1 week. On the other hand, VEGF is completely released within the first 24 h.

Formulation and in vitro characterization of Eudragit® L100 and Eudragit® L100-PLGA nanoparticles containing diclofenac sodium

The aim of this study was to formulate and characterize Eudragit® L100 and Eudragit® L100-poly(lactic-co-glycolic acid) (PLGA) nanoparticles containing diclofenac sodium. Diclofenac generates severe adverse effects with risks of toxicity. Thus, nanoparticles were prepared to reduce these drawbacks in the present study. These nanoparticles were evaluated for surface morphology, particle size and size distribution, percentage drug entrapment, and in vitro drug release in pH 6.8. The prepared nanoparticles were almost spherical in shape, as determined by atomic force microscopy. The nanoparticles with varied size (241-274 nm) and 25.8-62% of entrapment efficiency were obtained. The nanoparticles formulations produced the release profiles with an initial burst effect in which diclofenac sodium release ranged between 38% and 47% within 4 h. The extent of drug release from Eudragit® L100 nanoparticles was up to 92% at 12 h. However, Eudragit®/PLGA nanoparticles showed an initial burst release followed by a slower sustained release. The cumulative release at 72 h was 56%, 69%, and 81% for Eudragit®/PLGA (20:80), Eudragit®/PLGA (30:70) and Eudragit®/PLGA (50:50) nanoparticles, respectively. The release profiles and encapsulation efficiencies depended on the amount of Eudragit in the blend. These data demonstrated the efficacy of these nanoparticles in sustaining the diclofenac sodium release profile.

Ultrasonic resonator technology as a new quality control method evaluating gelatin nanoparticles

Nanomedicine is a quickly evolving field where more and more possible applications become evident and start entering clinical trials or even the market. However, the analytic methods are not always able to keep pace with the new formulations' demands. One example of a promising medical implementation is oligodeoxynucleotide (ODN) delivery by gelatin nanoparticles (GNPs). Currently, quality control is dependent on either some time consuming or destructive spectrometric, chromatographic or electrophoretic methods. A possible enlargement of the portfolio by Ultrasonic Resonator Technology (URT) is investigated here by subjecting plain GNPs in various sizes and concentrations as well as ODN-loaded GNPs to URT analysis. If calibrated by photon correlation spectroscopy (PCS) and other spectroscopy methods for each single nanoparticle system parameter, URT is an efficient and non-destructive technique and serves as a broad characterization method. URT is emphasized to play a possible future part in the size, concentration and ODN loading monitoring, e.g. of gelatin nanoparticles in the course of formulation development.

Dendrimer-based tumor cell targeting of fibroblast growth factor-1

Fibroblast Growth Factor Receptor (FGFR) is overexpressed in a wide variety of tumors, and therefore is an attractive target for drug delivery. Recombinant FGF-1 was purified and attached to a fifth-generation (G5) polyamidoamine dendrimer. The specific binding and internalization of this conjugate labeled with FITC was demonstrated by flow cytometry as well as by confocal microscopic analysis in cell lines expressing FGFR. The binding and uptake of FGF-conjugated dendrimers was completely blocked by excess nonconjugated FGF-1. Confocal microscopic analysis showed cytosolic as well as nuclear localization. Multivalent G5-FGF nanoparticles may serve as a platform for cytosolic as well as nuclear drug delivery in tumor cells, and as an FGF delivery agent for angiogenesis and wound healing. Our study shows for the first time the applicability of a dendrimer nanodevice for tumor cell targeting through FGFR.

Fabrication of a novel hybrid heart valve leaflet for tissue engineering: an in vitro study

The objective of this study was to fabricate biomatrix/polymer hybrid heart valve leaflet scaffolds using an electrospinning technique and seeded by mesenchymal stem cells. Mesenchymal stem cells were obtained from rats. Porcine aortic heart valve leaflets were decellularized, coated with basic fibroblast growth factor/chitosan/poly-4-hydroxybutyrate using an electrospinning technique, reseeded, and cultured over a time period of 14 days. Controls were reseeded and cultured over an equivalent time period. Specimens were examined biochemically, histologically, and mechanically. Recellularization of the hybrid heart valve leaflet scaffolds was significantly improved compared to controls. Biochemical and mechanical analysis revealed a significant increase of cell mass, 4-hydroxyproline, collagen, and strength in the hybrid heart valve leaflets compared to controls. This is the first attempt in tissue-engineered heart valves to fabricate hybrid heart valve leaflets using mesenchymal stem cells combined with a slow release technique and an electrospinning technique.

Nanoparticulate systems for growth factor delivery

The field of nanotechnology, which aims to control and utilize matter generally in 1-100 nm range, has been at the forefront of pharmaceutical development. Nanoparticulate delivery systems, with their potential to control drug release profiles, prolonging the presence of drugs in circulation, and to target drugs to a specific site, hold tremendous promise as delivery strategies for therapeutics. Growth factors are endogenous polypeptides that initiate intracellular signals to regulate cellular activities, such as proliferation, migration and differentiation. With improved understanding of their roles in physiopathology and expansion of their availability through recombinant technologies, growth factors are becoming leading therapeutic candidates for tissue engineering approaches. However, the outcome of growth factor therapeutics largely depends on the mode of their delivery due to their rapid degradation in vivo, and non-specific distribution after systemic administration. In order to overcome these impediments, nanoparticulate delivery systems are being harnessed for spatiotemporal controlled delivery of growth factors. This review presents recent advances and some disadvantages of various nanoparticulate systems designed for effective intact growth factor delivery. The therapeutic applications of growth factors delivered by such systems are reviewed, especially for bone, skin and nerve regeneration as well as angiogenesis. Finally, future challenges and directions in the field are presented in addition to the current limitations.

Methods for the preparation and manufacture of polymeric nanoparticles

This review summarizes the different methods of preparation of polymer nanoparticles including nanospheres and nanocapsules. The first part summarizes the basic principle of each method of nanoparticle preparation. It presents the most recent innovations and progresses obtained over the last decade and which were not included in previous reviews on the subject. Strategies for the obtaining of nanoparticles with controlled in vivo fate are described in the second part of the review. A paragraph summarizing scaling up of nanoparticle production and presenting corresponding pilot set-up is considered in the third part of the review. Treatments of nanoparticles, applied after the synthesis, are described in the next part including purification, sterilization, lyophilization and concentration. Finally, methods to obtain labelled nanoparticles for in vitro and in vivo investigations are described in the last part of this review.

Recent developments in nanoparticle-based drug delivery and targeting systems with emphasis on protein-based nanoparticles

BACKGROUND

Drug delivery systems with nm dimensions (nanoparticles [NPs]) are attracting increasing attention because they can sequester drugs in systemic circulation, prevent non-specific biodistribution, and target to specific tissues.

OBJECTIVE

We reviewed the recent literature pertinent to NP-based drug delivery, primarily emphasizing NPs fabricated from proteins.

METHODS

A summary of common NP fabrication techniques is provided along with the range of sizes and functional properties obtained. The NP properties critical for injectable drug delivery are reviewed, as well as the attempts to design 'tissue-specific' NPs.

RESULTS/CONCLUSIONS

It has been possible to design > 100 nm NPs from different biomaterials, and further understanding of in vivo stability and interactions with physiologic systems will lead to improved drug delivery systems.