The insulin-like growth factor 1 (IGF-1) is a pleiotropic hormone that regulates essential life-history traits and is known for its major contribution to determining individual ageing processes. High levels of IGF-1 have been linked to increased mortality and are hypothesised to cause oxidative stress. This effect has been observed in laboratory animals, but whether it pertains to wild vertebrates has not been tested. This is surprising because studying the mechanisms that shape individual differences in lifespan is important to understanding mortality patterns in populations of free-living animals. We tested this hypothesis under semi-natural conditions by simulating elevated IGF-1 levels in captive bearded reedlings, a songbird species with an exceptionally fast pace of life. We subcutaneously injected slow-release biodegradable microspheres loaded with IGF-1 and achieved a systemic 3.7-fold increase of the hormone within the natural range for at least 24 h. Oxidative damage to lipids showed marked sexual differences: it significantly increased the day after the manipulation in treated males and returned to baseline levels four days post-treatment, while no treatment effect was apparent in females. Although there was no overall difference in survival between the treatment groups, high initial (pre-treatment) IGF-1 and low post-treatment plasma malondialdehyde levels were associated with enhanced survival prospects in males. These results suggest that males may be more susceptible to IGF-1-induced oxidative stress than females and quickly restoring oxidative balance may be related to fitness. IGF-1 levels evolve under opposing selection forces, and natural variation in this hormone’s level may reflect the outcome of individual optimization.

Particulate antigen‐delivery systems are instrumental for therapeutic vaccination, aiming at improving the safety and efficacy of treatments by targeting specialized antigen‐presenting cells (APCs). However, the induction of potent adaptive immune responses, especially cellular immunity, remains a major challenge. Herein, a novel nanoparticulate antigen‐delivery system based on amphiphilic cyclodextrins (CDs) is developed as a platform for therapeutic cancer vaccination. Supramolecular nanosized CD structures are formed in aqueous media and loaded with peptide antigens. The nanoparticle's adjuvant capacity is tested in cell experiments with murine bone marrow‐derived dendritic cells (BMDCs) or macrophages and T cells. Peptide‐loaded nanoparticles cause upregulation of costimulatory molecules on BMDCs and facilitate activation and proliferation of antigen‐specific T‐lymphocytes in vitro. Correct processing for major histocompatibility complex (MHC) class‐I antigen presentation is demonstrated using a capped version of the ovalbumin‐derived peptide SIINFEKL (c‐SFL). After immunization of mice with peptide‐loaded CD nanoparticles, the frequencies of antigen‐specific and cytokine‐producing CD8 + T cells are increased. This work sheds light on the immune‐stimulating properties of amphiphilic CD nanoparticles and reveals their considerable potential as carriers for cancer vaccines.

Moulting is a crucial, yet often overlooked life-history stage in many animals, when they renew their integumental structures. This life-history stage is an energetically demanding somatic growth event that has particular importance in birds because feathers play a crucial role in flight, insulation and communication. Somatic growth processes are regulated by the evolutionarily conserved peptide hormone insulin-like growth factor 1 (IGF-1). However, the role of IGF-1 in feather growth remains unknown. In this study, we captured 41 juvenile free-living bearded reedlings (Panurus biarmicus) that had started their first complete moult and brought them into captivity. Then, we manipulated their circulating IGF-1 levels using poly-(lacticco-glycolid acid) microparticles (microspheres) that provide a sustained release of IGF-1. The treatment increased IGF-1 levels but did not affect the feather growth rate. However, 2 weeks after the treatment, birds in the increased IGF-1 group were moulting more feathers simultaneously than the controls and were at a more advanced stage of moult. Birds with experimentally increased IGF-1 levels had better quality feathers (measured by a lower number of fault bars) than the controls. These results suggest that an increase in IGF-1 does not speed up feather growth, but may alter moult intensity by initiating the renewal of several feathers simultaneously. This may shorten the overall moulting time but may imply costs in terms of IGF-1-induced oxidative stress.

With emerging supremacy, cancer immunotherapy has evolved as a promising therapeutic modality compared to conventional antitumor therapies. Cancer immunotherapy composed of biodegradable poly(lactic- co -glycolic acid) (PLGA) particles containing antigens and toll-like receptor ligands induces vigorous antitumor immune responses in vivo. Here, we demonstrate the supreme adjuvant effect of the recently developed and pharmaceutically defined double-stranded (ds)RNA adjuvant Riboxxim especially when incorporated into PLGA particles. Encapsulation of Riboxxim together with antigens potently activates murine and human dendritic cells, and elevated tumor-specific CD8 + T cell responses are superior to those obtained using classical dsRNA analogues. This PLGA particle vaccine affords primary tumor growth retardation, prevention of metastases, and prolonged survival in preclinical tumor models. Its advantageous therapeutic potency was further enhanced by immune checkpoint blockade that resulted in reinvigoration of cytotoxic T lymphocyte responses and tumor ablation. Thus, combining immune checkpoint blockade with immunotherapy based on Riboxxim-bearing PLGA particles strongly increases its efficacy.

Antigen cross-presentation to cytotoxic CD8+ T cells is crucial for the induction of anti-tumor and anti-viral immune responses. Recently, co-encapsulation of photosensitizers and antigens into microspheres and subsequent photochemical internalization (PCI) of antigens in antigen presenting cells has emerged as a promising new strategy for inducing antigen-specific CD8+ T cell responses in vitro and in vivo. However, the exact cellular mechanisms have hardly been investigated in vivo, i.e., which cell types take up antigen-loaded microspheres at the site of injection, or in which secondary lymphoid organ does T cell priming occur? We used spray-dried poly(lactic-co-glycolic acid) (PLGA) microspheres loaded with ovalbumin and the photosensitizer tetraphenyl chlorine disulfonate (TPCS2a) to investigate these processes in vivo. Intravital microscopy and flow cytometric analysis of the murine ear skin revealed that dendritic cells (DCs) take up PLGA microspheres in peripheral tissues. Illumination then caused photoactivation of TPCS2a and induced local tissue inflammation that enhanced CCR7-dependent migration of microsphere-containing DCs to tissue-draining lymph nodes (LNs), i.e., the site of CD8+ T cell priming. The results contribute to a better understanding of the functional mechanism of PCI-mediated vaccination and highlight the importance of an active transport of vaccine microspheres by antigen presenting cells to draining LNs.

Lifespan evolves as a compromise between antagonistic selection forces. Insulin-like growth factor 1 (IGF-1) is a pleiotropic hormone that regulates several life-history traits. High levels of IGF-1 have been linked to increased mortality, partly by causing oxidative stress. However, these effects have no experimental evidence in wild animals. We implanted microspheres loaded with exogenous IGF-1 into bearded reedlings, a common short-lived Eurasian songbird. The treatment elevated plasma IGF-1 levels for at least 24 h. Oxidative damage to lipids significantly increased the day after the manipulation in treated birds, but returned to baseline levels four days post-treatment. The treatment had no effect on survival over 16 months; however, birds with higher pre-treatment (baseline) IGF-1 levels had better survival prospects. These results suggest that, although high IGF-1 levels may induce oxidative damage, natural variation in this hormone’s level may reflect the outcome of individual optimization.

Cytotoxic T lymphocytes (CTLs) are key players in fighting cancer, and their induction is a major focus in the design of therapeutic vaccines. Yet, therapeutic vaccine efficacy is limited, in part due to the suboptimal vaccine processing by antigen-presenting cells (APCs). Such processing typically takes place via the MHC class II pathway for CD4 T-cell activation and MHC class I pathway for activation of CD8 CTLs. We show that a combination of skin photochemical treatment and immunization, so-called photochemical internalization (PCI) facilitated CTL activation due to the photochemical adjuvant effect induced by photosensitizer, oxygen, and light. Mice were immunized intradermally with antigen and photosensitizer, followed by controlled light exposure. PCI-treated mice showed strong activation of CD8 T cells, with improved IFN-γ production and cytotoxicity, as compared to mice immunized without parallel PCI treatment. Surprisingly, the CD8 T-cell effector functions were not impaired in MHC class II- or CD4 T-cell-deficient mice. Moreover, PCI-based vaccination caused tumor regression independent of MHC class II or CD4 T cells presence in melanoma bearing mice. Together, the data demonstrate that PCI can act as a powerful adjuvant in cancer vaccines, even in hosts with impaired T-helper functions.

The secondary and primary (mesobronchus) bronchi of chicken lung are lined by a typlcal respiratory epithelium: pseudostratified coiumnar ciliated with globet cells.Up to date, four constituting epithelial ceil types have been identified: ciliated, mucosecretory, basal and endocrine ceils.In this study a putative new epitheiial cell type, the brush-like cell, is described.The avian brush-like cells have only been found in the bronchial epithelia but never in the gas-exchange areas.They are scattered among the other epitheliai ceils, mainly ciliated cells, and their number is extremely low.The characteristic morphoiogical feature of these cells is an apical protruding cytopiasm with microvilli.This cell type is similar to that found in the iung of some mammalian and non-mammalian species.The functional roie of these cells in not yet clear; they couid carry out absorptive processes.

Event Abstract Back to Event Advanced therapeutic medicinal product for promoting nerve regeneration Patricia Sieber1, Elisabeth Kappos1, Sandhya Ananta2, Kirsten Haastert3, Silvio Hemmi4, Daniel Kalbermatten1, Bruno Gander2 and Srinivas Madduri1, 2, 5 1 University Hospital Basel, Department of reconstructive surgery, Switzerland 2 ETH Zurich, Institute of Pharmaceutical Sciences, Switzerland 3 Hannover medical school, Institute of neuroanatomy, Germany 4 University of Zurich, Institute of molecular lifesciences, Switzerland 5 University of basel, Department of biomedical engineering, Switzerland Introduction: Peripheral nerve reconstruction is critical and challenging due to lack of effective ways to create a complex, multifactorial and dynamic microenvironment required for axonal path finding. Here, we report on bioengineered nerve conduits (NCs) endowed with important biological functions, namely structural, cellular and molecular cues for supporting complex requirements of axonal path finding and target re-innervation. Materials and Methods: The required materials were developed and thoroughly characterized in vitro prior to animal testing. Rat Schwann cells were isolated, purified, and desired phenotype S100+ was confirmed by immunostaining. Efficient (99% transduction efficiency), tropism modified, recombinant adenovirus was generated using homologous genetic recombination process for mono or bicistronic expression of GDNF and NGF (Ad5-CMV-GDNF-IRES-NGF/F-RGD. Purified virus was used for genetic modification of Schwann cells (GMSCs), which were further analysed in vitro and in vivo for viability and transgene expression. Nanostructured NCs were made of collagen (CNC) or silk fibroin (SFNC) using a newly developed layer-by-layer fabrication method and enriched by using unmodified SCs or GMSCs, or GDNF and NGF proteins. Thus, the developed NCs encompassed 8 different compositions. Adult rats (Sprague Dawley, 250-300g) were randomly allocated into 9 groups (6 and 12 weeks; n=12 per group) for treating 10 mm sciatic nerve gap by using the variants of bioengineered NCs. Animal response for nerve regeneration was evaluated by measuring the anatomical, behavioural and electrophysiological recovery. For examining the potential induction of an immune response against the recombinant adenovirus, serum samples were collected and prepared for the virus neutralization assay. Results and Discussion: Resulting recombinant virus, within GMSCs, proved to be safe and efficacious both in vitro and in vivo in nerve crush injury model. SEM analysis of nanostructured collagen NC (CNC) and silk fibroin NC (SFNC) confirmed the alignment and stable adherence of nanofibers on the luminal surface. Further enrichment of NCs with biological functions such as SCs, GMSCs, and GDNF/NGF proteins produced 8 different NC types varying in cellular and trophic support. All biofunctionalized NCs augmented significantly axonal outgrowth of sensory or/and motor neurons in vitro, and determined differentially the extent of axonal elongation as well as growth direction in comparison with non-biofunctionalized NCs. The anatomical, behavioural and electrophysiological outcomes differed significantly between the treatment groups. The virus neutralization assay indicated absence of undesired immune response against the recombinant adenovirus used for genetic modification of the Schwann cells. Importantly, bioengineered collagen NCs carrying most important biological functions, in contrast to silk fibroin NCs, showed potential to overcome the present hurdles of nerve regeneration and matched well with autograft performance. Conclusion: This study not only revealed the importance of new bioengineering approach for creating dynamic and effective microenvironment for axonal path finding, but also demonstrated the impact of biomaterial composition (advanced therapeutic medicinal product for complex tissue organization) in mounting effective nerve tissue regeneration. We akcknowlege the enabling financial support by SNSF.References:[1] Madduri S, Michael P, Gadner B. Biomaterials 2010; 31:2323-34[2] Stoeckli E et al. J Cell Biol 1991; 112: 449-55 Keywords: Tissue Engineering, growth factor, nanotopography, complex tissue orgnization Conference: 10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016. Presentation Type: New Frontier Oral Topic: Biomimetic materials Citation: Sieber P, Kappos E, Ananta S, Haastert K, Hemmi S, Kalbermatten D, Gander B and Madduri S (2016). Advanced therapeutic medicinal product for promoting nerve regeneration. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf.FBIOE.2016.01.00219 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 28 Mar 2016; Published Online: 30 Mar 2016. Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Patricia Sieber Elisabeth Kappos Sandhya Ananta Kirsten Haastert Silvio Hemmi Daniel Kalbermatten Bruno Gander Srinivas Madduri Google Patricia Sieber Elisabeth Kappos Sandhya Ananta Kirsten Haastert Silvio Hemmi Daniel Kalbermatten Bruno Gander Srinivas Madduri Google Scholar Patricia Sieber Elisabeth Kappos Sandhya Ananta Kirsten Haastert Silvio Hemmi Daniel Kalbermatten Bruno Gander Srinivas Madduri PubMed Patricia Sieber Elisabeth Kappos Sandhya Ananta Kirsten Haastert Silvio Hemmi Daniel Kalbermatten Bruno Gander Srinivas Madduri Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

One of the greatest pharmaceutical challenges in vaccinology is the delivery of antigens to the cytosol of antigen-presenting cells (APCs) in order to allow for the stimulation of major histocompatibility complex (MHC) class I-restricted CD8(+) T-cell responses, which may act on intracellular infections or cancer. Recently, we described a novel method for cytotoxic T-lymphocyte (CTL) vaccination by combining antigens with a photosensitizer and light for cytosolic antigen delivery. The goal of the current project was to test this immunization method with particle-based formulations. Liposomes were prepared from dipalmitoylphosphatidylcholine and cholesterol, and the antigen ovalbumin (OVA) or the photosensitizer tetraphenyl chlorine disulfonate (TPCS2a) was separately encapsulated. C57BL/6 mice were immunized intradermally with OVA liposomes or a combination of OVA and TPCS2a liposomes, and light was applied the next day for activation of the photosensitizer resulting in cytosolic release of antigen from phagosomes. Immune responses were tested both after a prime only regime and after a prime-boost scheme with a repeat immunization 2 weeks post priming. Antigen-specific CD8(+) T-cell responses and antibody responses were analyzed ex vivo by flow cytometry and ELISA methods. The physicochemical stability of liposomes upon storage and light exposure was analyzed in vitro. Immunization with both TPCS2a- and OVA-containing liposomes greatly improved CD8(+) T-cell responses as compared to immunization without TPCS2a and as measured by proliferation in vivo and cytokine secretion ex vivo. In contrast, OVA-specific antibody responses (IgG1 and IgG2c) were reduced after immunization with TPCS2a-containing liposomes. The liposomal formulation protected the photosensitizer from light-induced inactivation during storage. In conclusion, the photosensitizer TPCS2a was successfully formulated in liposomes and enabled a shift from MHC class II to MHC class I antigen processing and presentation for stimulation of strong CD8(+) T-cell responses. Therefore, photosensitive particulate vaccines may have the potential to add to current vaccine practice a new method of vaccination that, as opposed to current vaccines, can stimulate strong CD8(+) T-cell responses.

Salmonella (S.) enterica infections are an important global health problem with more than 20 million individuals suffering from enteric fever annually and more than 200,000 lethal cases per year. Although enteric fever can be treated appropriately with antibiotics, an increasing number of antibiotic resistant Salmonella strains is detected. While two vaccines against typhoid fever are currently on the market, their availability in subtropical endemic areas is limited because these products need to be kept in uninterrupted cold chains. Hence, the development of a thermally stable vaccine that induces mucosal immune responses would greatly improve human health in endemic areas. Here, we have combined the high structural stability of Salmonella typhi outer membrane proteins (porins) with their microencapsulation into poly(lactic-co-glycolic acid) (PLGA) to generate an orally applicable vaccine. Encapsulated porins were protected from acidic degradation and exhibited enhanced immunogenicity following oral administration. In particular, the vaccine elicited strong S. typhi-specific B cell responses in Peyer's patches and mesenteric lymph nodes. In sum, PLGA microencapsulation substantially improved the efficacy of oral vaccination against S. typhi.

The generation of CTLs is crucial in the immunological fight against cancer and many infectious diseases. To achieve this, vaccine Ags need to be targeted to the cytosol of dendritic cells, which can activate CD8 T cells via MHC class I (MHCI). Therefore, such targeting has become one of the major objectives of vaccine research. In this study, we aimed to bypass the unwanted and default MHC class II Ag presentation and trigger MHCI presentation by using a photosensitizer that, upon light activation, would facilitate cytosolic targeting of codelivered Ag. Poly(lactide-co-glycolide) microparticles ∼1 μm size were loaded with OVA and the photosensitizer tetraphenyl chlorine disulphonate (TPCS2a) and administered intradermally in mice, which were illuminated 1 d later for activation of the photosensitizer. Immunization in the presence of TPCS2a significantly increased activation of CD8 T cells compared with immunization without TPCS2a and as measured by CD8 T cell proliferation, production of proinflammatory IFN-γ, TNF-α, and IL-2, and prevention of tumor growth. Cytotoxicity was demonstrated by granzyme B production in vitro and by in vivo killing of CFSE-labeled targets. CD4-dependent Ab responses were abrogated in mice immunized with TPCS2a-containing particles, suggesting that photosensitization facilitated a shift from default MHC class II toward MHCI Ag presentation. Hence, vaccine particles with Ag and photosensitizers proved an effective vehicle or adjuvant for stimulation of CTLs, and they may find potential application in therapeutic cancer vaccination and in prophylactic and therapeutic vaccination against intracellular infections.

Miconazole and itraconazole possess adequate membrane permeability, but only slight water solubility, which limits their bioavailability and antifungal effect. To increase their dissolution rate, the compounds were nanoground by media milling to produce nanosuspensions with mean particle size of approximately 210 nm and stabilized with sodium dodecylsulfate (SDS) in combinations with either cellulose ethers (HPC or HPMC) or poloxamers. During storage for 3 months at 25 °C, HPC/SDS stabilized more efficiently miconazole nanoparticles, while poloxamer 407/SDS performed better with itraconazole nanosuspensions. The stabilizing efficiency of the excipients was explained by physical-chemical drug-excipients interactions. The HPC/SDS-stabilized nanosuspensions were spray-dried or freeze-dried with and without the matrix formers mannitol or microcrystalline cellulose (MCC). In absence of matrix former, itraconazole particles agglomerated more extensively than miconazole particles, resulting in a low dissolution rate. Dissolution of the spray- or freeze-dried miconazole nanosuspension was enhanced in presence of mannitol or MCC (drug substance:excipient ratio of 1:1, w/w), as compared to the coarse drug suspension (twice the amount dissolved after 10 and 20 min). Spray-drying itraconazole nanosuspension in presence of mannitol or MCC also yielded fast dissolution (60% dissolved in less than 10 min as compared to 30-45 min with the coarse suspension). Freeze-dried itraconazole nanosuspensions did generally not dissolve substantially faster than freeze-dried coarse suspension. In conclusion, we were able to process miconazole and itraconazole successfully and under similar conditions into dry nanoparticulate drug products with enhanced in vitro performance.

Axonal repair and regeneration remain critical due to lack of appropriate delivery systems for efficient release of neurotrophic factors (NTFs). Recently, we have demonstrated the synergistic activity of nerve growth factor (NGF) and glial cell line-derived neurotrophic factor (GDNF) on axonal regeneration. Combined delivery of GDNF and NGF with individually controlled release kinetics may be crucial for exploiting their synergistic action on axonal elongation in animals. For engineering discrete NTF release kinetics, we have developed several nerve conduits (NCs) using collagen (Col) and silk fibroin (SF); the NC were made of Col or SF alone, or of Col and SF layers, or of Col/SF blends, all loaded with GDNF and NGF. All NC types provided sustained combined release of NGF and GDNF over 28 days. NC made of combinations of Col and SF showed reduced burst and more sustained dual release of GDNF and NGF. SF/Col-based NC scaffolds provide an adaptable delivery system for growth factors and hold potential for nerve regeneration and possibly for other tissue engineering applications.

Spatiotemporal release of growth factors from a delivery device can profoundly affect the efficacy of bone growth induction. Here, we report on a delivery platform based on the encapsulation of insulin-like growth factor I (IGF-I) in different poly(D,L-lactide) (PLA) and poly(D,L-lactide-co-glycolide) (PLGA) microsphere (MS) formulations to control IGF-I release kinetics. In vitro IGF-I release profiles generally exhibited an initial burst (14-36% of total IGF-I content), which was followed by a more or less pronounced dormant phase with little release (2 to 34 days), and finally, a third phase of re-increased IGF-I release. The osteoinductive potential of these different IGF-I PL(G)A MS formulations was tested in studies using 8-mm metaphyseal drill hole bone defects in sheep. Histomorphometric analysis at 3 and 6 weeks after surgery showed that new bone formation was improved in the defects locally treated with IGF-I PL(G)A MS (n=5) as compared to defects filled with IGF-I-free PL(G)A MS (n=4). The extent of new bone formation was affected by the particular release kinetics, although a definitive relationship was not evident. Local administration of IGF-I resulted in down-regulation of inflammatory marker genes in all IGF-I treated defects. The over-expression of growth factor genes in response to IGF-I delivery was restricted to formulations that produced osteogenic responses. These experiments demonstrate the osteoinductive potential of sustained IGF-I delivery and show the importance of delivery kinetics for successful IGF-I-based therapies.

The transition from organism-based traditional vaccines to the use of safer subunit vaccines has implemented the use of adjuvants to enhance immunogenicity. This study compares the potential of two types of polymeric microparticles as delivery systems for the model antigen ovalbumin. The delivery systems encompassed polyelectrolyte microcapsules, assembled via Layer-by-Layer technology, and PLGA microparticles fabricated by spray-drying. Mice were immunized subcutaneously either by a single injection or by two injections separated by four weeks with an equivalent dose of the OVA-loaded particles. Both particulate formulations mediated high, long-term IgG(1) responses whereas the IgG(2c) titers remained low. Additionally, Th1 and Th2 phenotype immune responses against OVA were assessed by quantifying the production of cytokines in CD4+ T-cells derived from the spleens of immunized mice at 6 months after the first injection. Immunization with particulate formulations led to significantly increased IL-2, IL-4, IL-10 and IFN-γ production by splenic CD4+ T-cells compared to control animals. LbL microcapsules and PLGA microparticles generated strong immune responses in vivo, characterized by a mixed Th1/Th2 type response with predominance of Th2 immunity. Both particulate formulations elicited a comparable type of immune response and appear to be promising for antigen delivery.

Nanosuspension technology is an attractive approach for the formulation and solubility enhancement of poorly water-soluble drug compounds. The technology requires adequate excipients for stabilizing the suspensions during nanogrinding and storage. This study aimed at establishing a near-infrared (NIR) method for assaying simultaneously the two nanoparticle stabilizers, sodium dodecyl sulphate (SDS) and hydroxypropylcellulose (HPC), in miconazole nanosuspensions. Second derivative of NIR signals was used to establish calibration curves in concentration ranges of interest of SDS (0.03-0.3%) and HPC (0.75-7.5%). The suitability and applicability of the NIR method was verified by evaluating the linearity, accuracy, precision, and specificity of the obtained data. The method was then used to quantify indirectly the amount of SDS and HPC adsorbed onto miconazole nanoparticles. Within the concentration range of interest, SDS adsorption increased up to 122 mu g/m(2) (4.2 x 10(-7) mol/m(2)) with increasing SDS concentration, and HPC adsorption was in the range of 800-1000 mu g/m(2) (21-27 x 10(-7) mol/m(2)) for nanosuspensions containing nominally 5% HPC and 12.5% or 20% miconazole. Interestingly, some of the adsorbed HPC was displaced upon increase of SDS concentration and adsorption. The data were also confirmed by surface tension measurements of aqueous solutions of SDS and HPC and nanosuspension supernatants. The availability of a fast and nondestructive method for quantifying simultaneously the adsorption of two stabilizers onto nanoground particles may not only speed up nanosuspension development, but also provide insight into the mechanisms of nanoparticle stabilization regarding competitive adsorption and electrostatic versus steric stabilization.