Various tissue engineering systems for cartilage repair have been designed and tested over the past two decades, leading to the development of many promising cartilage grafts. However, no one has... Show moreVarious tissue engineering systems for cartilage repair have been designed and tested over the past two decades, leading to the development of many promising cartilage grafts. However, no one has yet succeeded in devising an optimal system to restore damaged articular cartilage. Here, the design, assembly, and biological testing of a porous, chitosan/collagen-based scaffold as an implant to repair damaged articular cartilage is reported. Its gradient composition and trilayer structure mimic variations in natural cartilage tissue. One of its layers includes hydroxyapatite, a bioactive component that facilitates the integration of growing tissue on local bone in the target area after scaffold implantation. The scaffold was evaluated for surface morphology; rheological performance (storage, loss, complex, and time-relaxation moduli at 1 kHz); physiological stability; in vitro activity and cytotoxicity (on a human chondrocyte C28 cell line); and in vivo performance (tissue growth and biodegradability), in a murine model of osteoarthritis. The scaffold was shown to be mechanically resistant and noncytotoxic, favored tissue growth in vivo, and remained stable for 35 days postimplantation in mice. These encouraging results highlight the potential of this porous chitosan/collagen scaffold for clinical applications in cartilage tissue engineering. Show less
Articular cartilage is a connective tissue structure that is found in anatomical areas that are important for the movement of the human body. Osteoarthritis is the ailment that most often affects... Show moreArticular cartilage is a connective tissue structure that is found in anatomical areas that are important for the movement of the human body. Osteoarthritis is the ailment that most often affects the articular cartilage. Due to its poor intrinsic healing capacity, damage to the articular cartilage is highly detrimental and at present the reconstructive options for its repair are limited. Tissue engineering and the science of nanobiomaterials are two lines of research that together can contribute to the restoration of damaged tissue. The science of nanobiomaterials focuses on the development of different nanoscale structures that can be used as carriers of drugs / cells to treat and repair damaged tissues such as articular cartilage. This review article is an overview of the composition of articular cartilage, the causes and treatments of osteoarthritis, with a special emphasis on nanomaterials as carriers of drugs and cells, which reduce inflammation, promote the activation of biochemical factors and ultimately contribute to the total restoration of articular cartilage. Show less
Articular cartilage is a connective tissue structure that is found in anatomical areas that are important for the movement of the human body. Osteoarthritis is the ailment that most often affects... Show moreArticular cartilage is a connective tissue structure that is found in anatomical areas that are important for the movement of the human body. Osteoarthritis is the ailment that most often affects the articular cartilage. Due to its poor intrinsic healing capacity, damage to the articular cartilage is highly detrimental and at present the reconstructive options for its repair are limited. Tissue engineering and the science of nanobiomaterials are two lines of research that together can contribute to the restoration of damaged tissue. The science of nanobiomaterials focuses on the development of different nanoscale structures that can be used as carriers of drugs / cells to treat and repair damaged tissues such as articular cartilage. This review article is an overview of the composition of articular cartilage, the causes and treatments of osteoarthritis, with a special emphasis on nanomaterials as carriers of drugs and cells, which reduce inflammation, promote the activation of biochemical factors and ultimately contribute to the total restoration of articular cartilage. Show less
Pluijm, I. van der; Heijningen, P. van; Ijpma, A.; Burger, J.; Schoonderwoerd, K.; Sluiter, W.; ... ; Essers, J. 2017
Entrapment of antigens in mucoadhesive nanoparticles prepared from N-trimethyl chitosan (TMC) has been shown to increase their immunogenicity. However, because of their large size compared to... Show moreEntrapment of antigens in mucoadhesive nanoparticles prepared from N-trimethyl chitosan (TMC) has been shown to increase their immunogenicity. However, because of their large size compared to soluble antigens, particles poorly diffuse through the nasal epithelium. The aim of this work was to study whether nasal vaccination with a much smaller TMC-antigen nanoconjugate would result in higher antibody responses as compared to TMC nanoparticles. TMC was covalently linked to a model antigen, ovalbumin (OVA), using thiol chemistry. For comparison, TMC/OVA nanoparticles and solutions of OVA and a physical mixture of TMC and OVA were made. As shown previously for TMC/OVA nanoparticles, TMC-OVA conjugate prolonged the nasal residence time of the antigen. TMC-OVA conjugate diffused significantly better through a monolayer of lung carcinoma (Calu-3) cells than TMC/OVA nanoparticles did. Moreover, nasal immunization of mice with the conjugate resulted in significantly more OVA positive DCs in the cervical lymph nodes as compared to TMC/OVA nanoparticles. Mice nasally immunized with TMC-OVA conjugate produced high levels of secretory IgA in nasal washes and higher titers of OVA-specific IgG than mice immunized with TMC/OVA nanoparticles after a priming dose. Moreover, as compared to TMC/OVA nanoparticles, TMC-OVA conjugate induced a more balanced IgG1/IgG2a response. In conclusion, the TMC-antigen nanoconjugate improves nasal delivery and immunogenicity of the antigen. This suggests that efficient codelivery of antigen and adjuvant to DCs, rather than a particulate form of the antigen/adjuvant combination, is decisive for the immunogenicity of the antigen. Show less
Slutter, B.; Bal, S.; Keijzer, C.; Mallants, R.; Hagenaars, N.; Que, I.; ... ; Jiskoot, W. 2010
Nasal vaccination is a promising, needle-free alternative to classical vaccination. Nanoparticulate delivery systems have been reported to overcome the poor immunogenicity of nasally administered... Show moreNasal vaccination is a promising, needle-free alternative to classical vaccination. Nanoparticulate delivery systems have been reported to overcome the poor immunogenicity of nasally administered soluble antigens, but the characteristics of the ideal particle are unknown. This study correlates differences in physicochemical characteristics of nanoparticles to their adjuvant effect, using ovalbumin (OVA)-loaded poly(lactic-co-glycolic acid) nanoparticles (PLGA NP), N-trimethyl chitosan (TMC) based NP (TMC NP) and TMC-coated PLGA NP (PLGA/TMC NP). PLGA NP and PLGA/TMC NP were prepared by emulsification/solvent extraction and TMC NP by ionic complexation. The NP were characterized physicochemically. Their toxicity and interaction with and stimulation of monocyte derived dendritic cells (DC) were tested in vitro. Furthermore, the residence time and the immunogenicity (serum IgG titers and secretory IgA levels in nasal washes) of the nasally applied OVA formulations were assessed in Balb/c mice. All NP were similar in size, whereas only PLGA NP carried a negative zeta potential. The NP were nontoxic to isolated nasal epithelium. Only TMC NP increased the nasal residence time of OVA compared to OVA administered in PBS and induced DC maturation. After i.m. administration all NP systems induced higher IgG titers than OVA alone, PLGA NP and TMC NP being superior to PLGA/TMC NP. Nasal immunization with the slow antigen releasing particles, PLGA NP and PLGA/TMC NP, did not induce detectable antibody titers. In contrast, nasal immunization with the positively charged, fast antigen releasing TMC NP led to high serum antibody titers and sIgA levels. In conclusion, particle charge and antigen release pattern of OVA-loaded NP has to be adapted to the intended route of administration. For nasal vaccination, TMC NP, releasing their content within several hours, being mucoadhesive and stimulating the maturation of DC, were superior to PLGA NP and PLGA/TMC NP which lacked some or all of these characteristics. (C) 2010 Elsevier Ltd. All rights reserved. Show less
Purpose: The aim of this study is the development of a three-dimensional multicellular spheroid cell culture model for the longitudinal comparative and large-scale screening of cancer cell... Show morePurpose: The aim of this study is the development of a three-dimensional multicellular spheroid cell culture model for the longitudinal comparative and large-scale screening of cancer cell proliferation with noninvasive molecular imaging techniques under controlled and quantifiable conditions. Procedures: The human glioblastoma cell line Gli36 Delta EGFR was genetically modified to constitutively express the fluorescence protein mCherry, and additionally labeled with iron oxide nanoparticles for high-field MRI detection. The proliferation of aggregates was longitudinally monitored with fluorescence imaging and correlated with aggregate size by light microscopy, while MRI measurements served localization in 3D space. Irradiation with gamma-rays was used to detect proliferational response. Results: Cell proliferation in the stationary three-dimensonal model can be observed over days with high accuracy. A linear relationship of fluorescence intensity with cell aggregate size was found, allowing absolute quantitation of cells in a wide range of cell amounts. Glioblastoma cells showed pronounced suppression of proliferation for several days following high-dose gamma-irradiation. Conclusions: Through the combination of two-dimensional optical imaging and 3D MRI, the position of individual cell aggregates and their corresponding light emission can be detected. This allows an exact quantification of cell proliferation, with a focus on very small cell amounts (below 100 cells) using high resolution noninvasive techniques as a well-controlled basis for further cell transplantation studies. Show less
Hagenaars, N.; Mania, M.; Jong, P. de; Que, I.; Nieuwland, R.; Slutter, B.; ... ; Jiskoot, W. 2010
The nose is a promising immunization site and intranasal (in.) vaccination studies with whole inactivated influenza virus (WIV) adjuvanted with N,N,N-trimethylchitosan (TMC-WIV) have shown... Show moreThe nose is a promising immunization site and intranasal (in.) vaccination studies with whole inactivated influenza virus (WIV) adjuvanted with N,N,N-trimethylchitosan (TMC-WIV) have shown promising results. In this study, the influence of TMC on the i.n, delivery of WIV was studied in mice by comparing the nasal residence time and the specific location in the nasal cavity of WIV and TMC-WIV. Additionally, the local toxicity profile of the WIV formulations was assessed. In vivo fluorescence imaging was used to study the nasal residence time and the fate of the bulk vaccine in mice that received vaccines fluorescently labeled with IRDye800CW (R). An immunohistochemical (IHC) staining method for nasal cross-sections was developed to visualize the antigen in the nasal cavity. Therefore, mice were sacrificed at different time points after vaccination with various vaccine formulations and nasal cross-sections were made. The local toxicity was assessed using hematoxylin and eosin staining for the nasal cross-sections. No significant differences in the nasal residence time between WIV and TMC-WIV were observed. However, IHC revealed a striking difference in the location and distribution of WIV in the nasal cavity. When formulated as plain WIV, positive staining was mainly found in the nasal cavity, presumably in mucus blobs. TMC-coated WIV, on the other hand, was mostly present as a thin layer on the epithelial surfaces of the naso- and maxilloturbinates. This difference in staining pattern correlates with the observed differences in immunogenicity of these two vaccines and indicates that TMC-WIV results in a much closer interaction of WIV with the epithelial surfaces than WIV alone, potentially leading to enhanced uptake and induction of immune responses. This study further shows that both WIV and TMC-WIV formulations induce minimal local toxicity. Taken altogether, these results provide more insight in the mode of action and safety of TMC and justify further research to develop TMC-adjuvanted nasal vaccines. (C) 2010 Elsevier B.V. All rights reserved. Show less
Mezzanotte, L.; Michelini, E.; Kaijzel, E.; Que, I.; Carlotti, F.; Hoeben, R.C.; ... ; Roda, A. 2010
