H. P. Jennissen

H. P. Jennissen
University of Duisburg-Essen | uni-due · Institut für Physiologische Chemie

Full Professor

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243
Publications
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3,474
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Publications

Publications (243)
Article
Full-text available
Adsorbate biohybrids for BMP-2 delivery based on electrospun PDLLA-nanofiber fleeces loaded with 0.6 μg/cm2 rhBMP-2COL (E. coli) strongly induced microvessel- like structures when incubated for 14 days in cocultures of human outgrowth endothelial cells (OEC) together with human primary osteoblasts (pOB). Higher loaded rhBMP-2COL biohybrids (4.6 μg/...
Article
Full-text available
Protein adsorption on solid surfaces is characterized by multivalence, binding-unit overlap, sequential adsorption, surface allosterics, lateral interactions and pronounced adsorption-desorption hysteresis, giving rise to the sequential, hystallosteric, adsorption model ("SHA model"). Adsorption isotherms of fibrinogen on a titanium miniplates and...
Article
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Protein adsorption is the first fundamental interaction between the human body and a foreign surface. The sum of all proteins in this adherent proteinaceous layer comprises the implant proteome. The in situdental implant proteome (implantome) was eluted from four implants of two wettabilities after a 2-min dipping in the humor operationis of maxill...
Article
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Protein adsorption studies returned to the focus of medical therapeutics, when it was found that up to 2500 non-plasma proteins adsorbed to hip implants during arthroplastic surgery, challenging peri-implant healing models. Questions have re-emerged as to the implications of uncontrolled protein unfolding after adsorption. In past studies on the co...
Article
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Immobilizing a single growth factor such as rhBMP-2 on Implant materials can significantly increase the integration of implants into bone in animals. Paradoxically the effective osteoinductive dose of rhBMP-2 in humans is ca. 100-1000-fold higher than in animals and may induce serious side effects in spine fusion surgery. In physiological bone heal...
Article
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Implantomics is the science of the implantome. The implantome is a blend of the two terms implant and proteome. The proteome is defined as the protein complement of the genome. The term proteome also implies the mass screening of proteins for the determination of all proteins - and indirectly of all genes - involved in a certain tissue or organ res...
Article
Purpose Aseptic loosening in total joint replacement due to insufficient osteointegration is an unsolved problem in orthopaedics. The purpose of our study was to obtain a picture of the initial protein adsorption layer on femoral endoprosthetic surfaces as the key to the initiation of osseointegration. Experimental design This paper describes the...
Article
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The surface design of titanium implants influences not only the local biological reactions but also affects at least the clinical result in orthopaedic application. During the last decades, strong efforts have been made to improve osteointegration and prevent bacterial adhesion to these surfaces. Following the rule of "smaller, faster, cheaper", na...
Patent
Full-text available
A process for the production of a storable implant with aqueous an ultrahydrophilic surface, the process comprising the steps of: providing an implant with an ultrahydrophilic surface, said ultrahydrophilic surface comprising a metal, metallic alloy, or ceramic material with dynamic contact angles from 0° to 10° upon wetting of the surface of the i...
Article
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The mechanisms of peri-implant
Article
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New methodologies are a major driving force of scientific progress. In this case the finding that contact angles can be expressed as complex numbers offers the possibility of a much refined analysis beyond zero degrees of rough ultra-/superhydrophilic, (now called hyperhydrophilic), metal surfaces, which play a distinct role in dental and orthopedi...
Chapter
Hydrophobic interaction chromatography (HIC) – today a key method in the purification of monoclonal antibodies – involves the separation of protein molecules in their native and biologically active state owing to a differential interaction of these molecules with hydrophobic sites on the surface of a solid support. Therefore, an understanding of th...
Article
Full-text available
Ultrahydrophilic titanium miniplates with sandblasted and acid etched (SLA) surfaces were protected from loss of hydrophilicity by an exsiccation layer of salt and stored in a dry state. Various salts in different concentrations were tested in respect to their conservation capacity and optical appearance. Potassium phosphate buffer in a specified c...
Article
Complex contact angles of water on rough surfaces have been described to consist of a real part for ideal wetting and of an imaginary part for non-ideal wetting (Jennissen, 2011, 2014). The concept of imaginary contact angles has accordingly been successfully applied to the analysis of hyperhydrophilic rough surfaces. The origin of the imaginary pa...
Patent
Full-text available
The invention concerns a method for the production of a product having a polymer matrix, products which can be produced in accordance therewith and the use thereof.
Article
A general mathematical form for contact angles on surfaces is suggested, offering fundamental new insights into describing wettability phenomena, which may be of considerable relevance to many fields of science. It was found that the Young equation - although physically well understood on ideal surfaces - is not unique, but a special case of a more...
Article
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The objective of the present work is to fabricate and develop growth factor-PDLLA nano-composites by electrospinning into 2D fleece or 3D tubular scaffolds that can mimic the nature and function of the native extracellular matrix of bone tissue or artificial blood vessels. The bioactive growth factors 125 I-rhVEGF 165 , 125 I-rhBMP-2 and the fibrou...
Article
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Electro spun PDLLA-nanofibers were functionalized with 125 I-rhBMP-2 and 125 I-rhVEGF165, either by protein-adsorption to, or by incorporation into electrospun PDLLA-nanofibers. Both, adsorbed and incorporated growth factors could be visualized via autoradiography. By fitting the release data according the two phase exponential decay, release rates...
Article
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For the successful regeneration of lost bone, the use of biomaterial-based substitutes in combination with factors that promote the regenerative process, such as vascular endothelial growth factor (VEGF) or bone morphogenetic protein 2 (BMP-2), might be promising. In this study, a model was used which generated capillary-like vessels by co-cultivat...
Conference Paper
Full-text available
Two methods of contact angle measurement are applied on screw type dental implants composed of titanium with different surfaces: The standard Wilhelmy method (dynamic measurement) and an extended sessile drop method (static measurement), where droplets with a volume in the picoliter range are generated. Both methods lead to comparable but in detail...
Article
Full-text available
Imaginary contact angles underlying hyperhydrophilicity and the Inverse Lotus Effect introduce a fundamental new development in the area of contact angles and wettability. Just as the Lotus Effect expanded hydrophobicity beyond the maximal contact angle of 119° on a smooth surface, the Inverse Lotus Effect expands hydrophilicity beyond the minimal...
Article
Full-text available
Two methods of contact angle measurement are applied on screw type dental implants composed of titanium with different surfaces: The standard Wilhelmy method (dynamic measurement) and an extended sessile drop method (static measurement), where droplets with a volume in the picoliter range are generated. Both methods lead to comparable but in detail...
Article
Full-text available
Sandblasted titanium screw type implants were acid-etched by two different methods using a semiautomatic wet chemical processing platform. Both etching methods led to homogenous, micro-structured and hyperhydrophilic surfaces making them especially suitable for dental applications. However processing time and procedural complexity differ greatly be...
Article
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Composite tablets of human recombinant bone morphogenetic protein 2 (rhBMP-2) and poly-(D,L)-lactide (PDLLA) (1-2 mg rhBMP-2/g PDLLA) were prepared by foaming of PDLLA with supercritical CO 2. Release kinetics of rhBMP-2 were measured by a continuous flow and a batch dilution method at 22°C and 50 °C respectively. In both cases a two-phase first-or...
Article
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The assembly and stability of polyelectrolyte multilayers (PEMs) was studied with the tracer 125 I-Poly-L-lysine together with chondroitin sulphate on microstructured titanium surfaces (µSLA). PEM assembly followed an exponential growth curve, which is mimicked by rhBMP-2 binding on glass slides during assembly. PEM disassembly occurred with a half...
Article
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Recently imaginary contact angles were introduced to monitor hydrophilicitiy beyond a contact angle of zero degrees. This discovery has never been systematically applied to a defi ned surface. Therefore, a batch of 30 ultrahydrophilic titanium miniplates (θ ≤ 10°, no hysteresis), prepared by sand-blasting with large grit and acid etching (SLA), was...
Article
Hydrophobic interaction chromatography (HIC) involves the separation of protein molecules in their native and biologically active state owing to a differential interaction of these molecules with hydrophobic sites on the surface of a solid support. In the separation process, hydrophobic patches on the protein surface interact with hydrophobic molec...
Patent
Full-text available
The invention relates to an implant with a structured surface and to methods for rationally producing such structured surfaces, and to methods for determining the wetting properties of said implants. The aim of these surfaces is to obtain structures resulting in properties displaying complex contact angles in the hyperhydrohilic range. [1] Jenniss...
Article
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Angiogenesis and osteogenesis are closely related processes sharing some essential mediators like VEGF (Vascular Endothelial Growth Factor) and BMP-2 (Bone Morphogenetic Protein-2). As vascularization is crucial to bone formation biofunctionalization of bone replacement materials with both of these proteins may result in enhanced bone formation. He...
Article
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With acid hydrophilized rough titanium plasma sprayed (TPS) miniplates (10.4 x 5.2 x 1.7 mm; Ra = 22 With acid hydrophilized rough titanium plasma sprayed (TPS) miniplates (10.4 x 5.2 x 1.7 mm; Ra = 22 μm; rm = 8) we discovered that ca. 20% of the data in each Wilhelmy balance measurement corresponded to "forbidden" data of the type cos θ > 1.0. It...
Article
The complete wetting of rough surfaces is only poorly understood, since the underlying phenomena can neither be described by the Cassie-Baxter nor the Wenzel equation. An experimental accessiblility by the sessile drop method is also very limited. The term “superhydrophilicity” was an attempt to understand the wetting of rough surfaces, but a clear...
Article
Although Wilhelmy balance measurements have been reported to yield undefined values of the type cos θ > 1, this phenomenon often goes unnoticed because commercial instruments fail to report this error, listing a contact angle of zero instead. On rough superhydrophilic surfaces such "undefined" values appear much more frequent, but a mathematical fr...
Article
Ultra-hydrophilic titanium surfaces can be prepared in a variety of ways by acid etching. However such surfaces are unstable in air and in water so that a storage for several years, as is necessary for clinical use, is a major problem. Ultrahydrophilic surfaces on miniplates prepared by chromosulfuric acid (CSA) enhancement showing dynamic advancin...
Article
The main objectives of the study described below were of two-fold nature: (1) to examine if rhBMP-2-biocoated implants in a pig model could lead to ectopic bone formation and (2) if quantitative and/or qualitative differences could be found between adhesively and covalently bonded BMP II using the scintigraphic method. In order to examine these cen...
Article
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A functionalization is required for calcium phosphate-based bone substitute materials to achieve an entire bone remodeling. In this study it was hypothesized that a tailored composite of tricalcium phosphate and a bioactive glass can be loaded sufficiently with rhBMP-2 for functionalization. A composite of 40 wt% tricalcium phosphate and 60 wt% bio...
Article
Titanium alloys are frequently surface-modified by plasma vapor deposition of cp titanium (titanium plasma spraying, TPS; Ti-PVD surface) for clinical use. Such surfaces are extremely rough with Ra values of 30 μm. Unmodified surfaces of Ti-PVD display apparent static contact angles of θS ˜ 145° which are in the ultra-/super-hydrophobic range and i...
Article
Ultra-hydrophilic titanium surfaces can be prepared in a variety of ways by acid etching. However such surfaces are unstable in air and in water so that a storage for several years, as is necessary for clinical use, is a major problem. Ultrahydrophilic surfaces on miniplates prepared by chromosulfuric acid (CSA) enhancement showing dynamic advancin...
Article
Recombinant human BMP-2 (rhBMP-2) was immobilized non-covalently and covalently as a monolayer on plasma vapour deposited (PVD) porous commercially pure titanium surfaces in amounts of 5-8 μg cm(-2), providing a ca. 10-fold increase vs. previously reported values. Dissociation of the immobilized [125I]rhBMP-2 from the surface occurred in a two-phas...
Article
Full-text available
The selective degradation of many proteins in eukaryotic cells is carried out by the ubiquitin system. In this pathway, proteins are targeted for degradation by covalent ligation to ubiquitin, a highly conserved protein [1]. Ubiquitylated proteins were degraded by the 26S proteasome in an ATP-depended manner. The degradation of ubiquitylated protei...
Article
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Kurzfassung In der Literatur werden zahlreiche Versuche beschrieben, die Bildung von neuem Knochen durch eine Kombination von Knochenersatzmaterialien mit BMP-2 zu steigern. Ein großes Problem in der chirurgischen Anwendung stellt jedoch die Wasserlöslichkeit des BMP-2 dar, die zu einer sehr schnellen Verteilung des Proteins im Körper führt. Die Fr...
Article
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Chicken eggs in the early phase of breeding are between in vitro and in vivo systems and provide a vascular test environment not only to study angiogenesis but also to study tumorigenesis. After the chick chorioallantoic membrane (CAM) has developed, its blood vessel network can be easily accessed, manipulated and observed and therefore provides an...
Article
Full-text available
Recombinant human bone morphogenetic protein-2 (rhBMP-2) is a growth factor of the transforming growth factor-beta superfamily. Members of this protein family are involved in the development of various mammalian tissues, including the inner ear. As their notations indicate, they also have well-known effects on bone formation and regeneration. In th...
Article
The kinetics of development of ultra-hydrophilicity by concentrated chromosulfuric acid action at 240°C on titanium and medicinal 316L steel miniplates have been measured by a temperaturejump method. It is shown here that ultra-hydrophilicity (contact angle <10°, absent contact angle hysteresis) is fully developed on electropolished titanium, anodi...
Patent
Full-text available
In the present method it is shown that also unphysiological, extreme pH values play a very important role in the amount of adsorbed growth factors. Thus acidic values in the range of pH 4 to 5 and alkaline values in the range of pH 9 to pH 11 allow high Loading values in the short time of at least 30 minutes. These extreme pH-vaues do not infringe...
Article
Full-text available
Nanoparticle (NP)-based delivery has gained importance for improving the potency of therapeutic agents. The bovine serum albumin (BSA) NPs, obtained by a coacervation process, was modified by electrostatic adsorption of cationic polyethylenimine (PEI) to NP surfaces for delivery of bone-inducing growth factor, bone morphogenetic protein-2 (BMP-2)....
Patent
Full-text available
A PDLLA/CaCO3 mixture was precipitated in ethanol, dried and milled to a fine powder and mixed with varying amounts of rhBMP-2. This composite-powder was foamed with supercritical CO2 resulting in rectangular tablets (10x5x2 mm, ~ 30 mg total weight) leading to a rhBMP-2 content of 0.66-2.6 mg BMP-2/g PDLLA. Newly formed bone increased significantl...
Article
The covalent and non-covalent immobilization of growth factors such as recombinant human bone morphogenetic protein 2 (rhBMP-2) on metals and bone replacement materials in bioactive form is a recent development. Up to now the immobilization technology usually involved the chemical modification and activation of the biomaterial surface followed by a...
Article
On the basis of their osteoinductive properties bone morphogenetic proteins (BMPs) are used today in clinical therapy such as the treatment of spinal disorders or healing defects in tibia fractures. A major biochemical function of these molecules is their binding to a large number of other proteins to fulfil their biological role. Two of these BMP-...
Article
In the international symposium „Biomaterials 2006” the German Society of Biomaterials (DGBM), the organizers of the XIXth „Aachen Colloquium on Biomaterials” and the organizers of the 9th „International Essen Symposium on Biomaterials and Biomechanics: Fundamentals and Clinical Applications” pooled forces thus bundling the potentials of the state o...
Article
Full-text available
We hypothesized that 20S proteasome is present and functional in the extracellular alveolar space in humans. Proteasomal activity was measured in bronchoalveolar lavage (BAL) supernatant from eight humans using specific proteasomal fluorogenic substrates and I(125)-albumin with and without specific proteasome inhibitors. Furthermore, gelfiltration,...
Patent
Full-text available
Verfahren zur Herstellung eines Implantates mit einer ultrahydrophilen Oberfläche, bei dem man die Oberfläche des Implantates so lange mit einem Oxidationsmittel behandelt, um auf der Oberfläche des Metalls eine Oxidschicht zu erzielen, bis sich eine Kontaktwinkelhysterese von weniger als 5° bei Benetzung der Oberfläche des Implantates mit Wasser e...
Patent
Full-text available
The ultrahydrophilic surface is prepared in two steps: (i) Immersing the metal implant in chromosulphuric acid having a density of more than 1.40g/cm3 , at a temperature of above 200°C, for a period of from 10 to 90 minutes; and (ii) quenching the metal implant by immersion in concentrated sulphuric acid at a temperature of15° to 25° C. and washing...
Patent
Full-text available
The ultrahydrophilic surface is prepared in two steps: (i) Immersing the metal implant in chromosulphuric acid having a density of more than 1.40g/cm3 , at a temperature of above 200°C, for a period of from 10 to 90 minutes; and (ii) quenching the metal implant by immersion in concentrated sulphuric acid at a temperature of15° to 25° C. and washing...
Article
Full-text available
The aim of the present study was to investigate bone formation to recombinant human bone morphogenetic protein-2 (rhBMP-2)-biocoated and rhBMP-2-nonbiocoated titanium implants after implantation in dogs. Implantation of sand-blasted and acid-etched (C), chromosulfuric acid surface-enhanced (CSA), and rhBMP-2-biocoated CSA [BMP-A: noncovalently immo...
Article
A rational application of hydrophobic interaction chromatography (HIC) to the purification of proteins has remained an enigma in spite of over 30 years of research. The critical hydrophobicity parameter, which can be determined from a concentration series of n-alkyl Sepharose 4B (Seph-Cn) offers the possibility of adapting the HIC gel to the needs...
Patent
Full-text available
The present invention is characterized by the findings that the use of amphiphilic tensides in the adsorption buffer , can improve the surface absorption characteristics of materials which serve as implant materials, made from metals, alloys, ceramic materials and combinations thereof. The "conformational Enhancer" (CHAPS: 3-[(3-Cholamidopropyl)-di...
Article
Hydroxyapatite (HAP) has a great potential as a bone replacement material because of its similarity to the crystal structure of inorganic matrix of bone. Several years ago we showed that porous hydroxyapatite ceramics (Endobon, Merck) can be covalently modified for the immobilization of proteins [Jennissen, H.P. (1999) PCT Patent WO9926674A2] openi...