Table of Contents

Volume 2, Issue 1

  January/February/March 2012

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REVIEWS

Open Access Article

Regenerative therapy and tissue engineering for the treatment of end-stage cardiac failure: New developments and challenges

G.T. Finosh and Muthu Jayabalan
Abstract | Full Text | PDF

Regeneration of myocardium through regenerative therapy and tissue engineering is appearing as a prospective treatment modality for patients with end-stage heart failure. Focusing on this area, this review highlights the new developments and challenges in the regeneration of myocardial tissue. The role of various cell sources, calcium ion and cytokine on the functional performance of regenerative therapy is discussed. The evolution of tissue engineering and the role of tissue matrix/scaffold, cell adhesion and vascularisation on tissue engineering of cardiac tissue implant are also discussed.

Open Access Article

Resolving the calcium phosphate-bone interface: A review of discoveries with light and electron microscopy

Kathryn Grandfield, Anders Palmquist, Håkan Engqvist and Peter Thomsen
Abstract | Full Text | PDF

It has long been known that the interfacial relationship between synthetic materials and tissue is influential in the success of implant materials. Instability at the implant interface has been shown, in some cases, to lead to complete implant failure. Bioceramics, and in particular calcium phosphates, form a large fraction of the implantable devices on the market today due to the biocompatibility they exhibit in contact with bone and tooth-like tissues. The characterization of such bioceramic-tissue interfaces has played a crucial role in understanding the behavior of bioceramics in vivo. In this review, we shed light on the preparation methods, technological approaches and key advances in resolving the interface between calcium phosphate bioceramics and bone, and share a future outlook on this field.




REPORTS

Open Access Article

Maintenance of α₁-antitrypsin activity by means of co-application of hypochlorous acid-scavengers in vitro and in the supernatant of polymorphonuclear leukocytes: As a basis for a new drug delivery approach

Maria Schönberg, Uta Reibetanz, Sophie Rathmann and Jacqueline Leßig
Abstract | PDF

Tissue destruction, pain and loss of function in chronically inflamed tissues can result from noxious agents released from myeloperoxidase (MPO) and its highly reactive product hypochlorous acid (HOCl) or proteases such as neutrophil elastase (NE).

 

Currently there exists a high demand for medications that provide gentle treatments, free from side effects inherent in those prescribed today. One method to circumvent side effects is through the use of locally applied drug delivery. In contrast to systemic therapy, the main advantages of transport systems are the low dosages of drug with a time-controlled delivery.

The aim of this study was to ascertain interactions of NE and its inhibitor α₁-antitrypsin (AT), the influence of hypochlorous acid (HOCl), as well as its scavengers, in order to define an effective mixture of drugs acting in a synergistic way which can be applied by means of drug delivery systems. These investigations determine the effective amounts of AT/HOCl-scavengers that drug mixtures need for delivery under inflammatory conditions in order to prevent tissue damage. AT was shown to inhibit NE in a dose-dependent manner, whereas a physiological concentration of 1.14 µM AT caused a significant NE inhibition (78%, pH 7.5). The concomitant existence of MPO/HOCl inactivated AT in a dose-dependent manner as well. To regain AT efficacy, HOCl-scavengers, such as l-methionine, α-aminosalicylic acid and cefoperazone were additionally applied.

Finally, AT was assembled as surface layer onto layer-by-layer biopolymer-coated microcarriers and carrier phagocytosis by polymorphonuclear leukocytes could be shown.

Open Access Article

Realization of a poro-elastic ultrasound replica of pulmonary tissue

Andrea Spinelli, Bruna Vinci, Annalisa Tirella, Marco Matteucci, Luna Gargani, Arti Ahluwalia, Claudio Domenici, Eugenio Picano and Piero Chiarelli
Abstract | Full Text | PDF

In this work we describe the fabrication of a biocompatible hydrophilic scaffold composed of cross-linked gelatin that mimics the porous three-dimensional structure of pulmonary tissue as well as its water content and mechanical properties. The lung replica also reproduces the characteristic sonographic signs of pulmonary interstitial syndrome, the B-lines or ultrasound lung comets.

Open Access Article

Implanted neonatal human dermal fibroblasts influence the recruitment of endothelial cells in mice

Susana G. Guerreiro, Christoph Brochhausen, Rita Negrão, Mário A. Barbosa, Ronald E. Unger, C. James Kirkpatrick, Raquel Soares and Pedro L. Granja
Abstract | Full Text | PDF

The vascularization of new tissue within a reasonable time is a crucial prerequisite for the success of different cell- and material-based strategies. Considering that angiogenesis is a multi-step process involving humoral and cellular regulatory components, only in vivo assays provide the adequate information about vessel formation and the recruitment of endothelial cells. The present study aimed to investigate if neonatal human dermal fibroblasts could influence in vivo neovascularization. Results obtained showed that fibroblasts were able to recruit endothelial cells to vascularize the implanted matrix, which was further colonized by murine functional blood vessels after one week. The vessels exhibited higher levels of hemoglobin, compared with the control matrix, implanted without fibroblasts, in which no vessel formation could be observed. No significant differences were detected in systemic inflammation. The presence of vessels originated from the host vasculature suggested that host vascular response was involved, which constitutes a fundamental aspect in the process of neovascularization. Fibroblasts implanted within matrigel increased the presence of endothelial cells with positive staining for CD31 and for CD34 and the production of collagen influencing the angiogenic process and promoting the formation of microvessels. New strategies in tissue engineering could be delineated with improved angiogenesis using neonatal fibroblasts.