Search

This article reports an enhanced solvent casting/particulate (salt) leaching (SCPL) method developed for preparing three-dimensional porous polyurethane (PU) scaffolds for cardiac tissue engineering. The solvent for the preparation of the PU scaffolds was a mixture of dimethylformamide (DFM) and tetrahydrofuran (THF). The enhanced method involved the combination of a conventional SCPL method and a step of centrifugation, with the centrifugation being employed to improve the pore uniformity and the pore interconnectivity of scaffolds. Highly porous three-dimensional scaffolds with a well interconnected porous structure could be achieved at the polymer solution concentration of up to 20% by air or vacuum drying to remove the solvent. When the salt particle sizes of 212-295, 295-425, or 425-531 µm and a 15% w/v polymer solution concentration were used, the porosity of the scaffolds was between 83-92% and the compression moduli of the scaffolds were between 13 kPa and 28 kPa. Type I collagen acidic solution was introduced into the pores of a PU scaffold to coat the collagen onto the pore walls throughout the whole PU scaffold. The human aortic endothelial cells (HAECs) cultured in the collagen-coated PU scaffold for 2 weeks were observed by scanning electron microscopy (SEM). It was shown that the enhanced SCPL method and the collagen coating resulted in a spatially uniform distribution of cells throughout the collagen-coated PU scaffold.

As proposed in McAuliffe, Winter, Chadwick and Hargreaves (2008), academagogy could be used as an “umbrella” term allowing the teacher to select from a range of teaching approaches – pedagogy (teacher as source of all information to student without power or knowledge), andragogy (teacher as source of information for adult student), or heutagogy (student with knowledge seeking information from teacher to fill the gaps in their own knowledge). During Semester 1, 2009, one of the authors of this paper decided to treat his third-year students in a more heutagogical manner by allowing them to experience ownership of their own learning. This article is a case study of that experience which reveals that, although initially more time-consuming, academagogy can result in better student outcomes.

Theories on teaching and learning for adult learners are constantly being reviewed and discussed in the higher educational environment. Theories are not static and appear to be in a constant developmental process. This paper discusses three of these theories: pedagogy, andragogy and heutagogy. It is argued that although educators engage in many of the principles of either student-centered (andragogy) and self-determined (heutagogy) learning, it is not possible to fully implement either theory. The two main limitations are the requirements of both internal and external stakeholders, such as accrediting bodies and requirements to assess all student learning. A reversion to teacher-centered learning (pedagogy) ensues. In summary, we engage in many action-oriented learning activities but revert to teacher-centered approaches in terms of content and assessment.

Academic staff within the QUT Faculty of Built Environment and Engineering are exploring ways to incorporate andragogical (student-centred) and heutagogical (self-determined) approaches to education into undergraduate programs, rather than relying on a purely pedagogical (teacher-centred) approach – an academagogic approach, where the most appropriate parts of various theories of learning are utilised. Moving to academagogy is more than a change; it will be a transition. Consideration will be required to assist teaching staff to navigate through new ways of knowing about what they are doing. The identities of these staff members will need to be moved from "experts expounding information to students" and will have to be rebuilt as facilitators/guides of knowledge dissemination for diverse groups of students. Within this, issues of change fatigue may need to be considered and addressed, along with those of leadership and trust. It will also be critical to review experiences of evaluation, as this is the area of most challenge in moving towards student-centred and self-determined education.

Theories on teaching and learning for adult learners are constantly being reviewed and discussed in the higher educational environment. Theories are not static and appear to be in a constant developmental process. This paper discusses three of these theories; pedagogy, andragogy and heutagogy. It is argued that although educators engage in many of the principles of either student-centered (andragogy) and self-determined (heutagogy) learning, it is not possible to fully implement either theory. The two main limitations are the requirements of both internal and external stakeholders such as accrediting bodies and requirements to assess all student learning. A reversion to teacher-centered learning (pedagogy) ensues. In summary, we engage in many action-oriented learning activities but revert to teacher-centered approaches in terms of content and assessment.

The results of a recent study have shown that there is a severe shortage of donor hearts to meet the demand of patients suffering from acute heart failures, and patients who received a left ventricular assist device (LVAD) have extended lives. However, some of them develop right heart failure syndrome, and these patients required a right ventricular assist device (RVAD). Hence, current research focus is in the development of a bi-ventricular assist device (Bi-VAD). Computational Fluid Dynamics (CFD) is useful for estimating blood damage for design of a Bi-VAD centrifugal heart pump to meet the demand of the left and right ventricles of a normal hearts with a flow rate of 5 lit/min and the supply pressure of 100 mmHg for the left ventricle and 20 mmHg for the right ventricle. Numerical studies have been conducted to predict pressure, flow rate, the velocity profiles, and streamlines in a continuous flow Bi-VAD using. Based on the predictions of numerical simulations, only few flow regions in the Bi-VAD exhibited signs of velocity profiles and stagnation points, thereby signifying potentially low levels of thrombogenesis.

The results of a recent study have shown that there is a severe shortage of donor hearts to meet the demand of patients suffering from acute heart failures, and patients who received a left ventricular assist device (LVAD) have extended lives. However, some of them develop right heart failure syndrome, and these patients required a right ventricular assist device (RVAD). Hence, current research focus is in the development of a bi-ventricular assist device (Bi-VAD). Computational Fluid Dynamics (CFD) is useful for estimating blood damage5 for design of a Bi-VAD centrifugal heart pump to meet the demand of the left and right ventricles of a normal hearts with a flow rate of 5 lit/min and the supply pressure of 100mmHg for the left ventricle and 20mmHg for the right ventricle. Numerical studies have been conducted to predict pressure, flow rate, the velocity profiles, and streamlines in a continuous flow Bi-VAD. Based on the predictions of numerical simulations, only few flow regions in the Bi-VAD exhibited signs of velocity profiles and stagnation points, thereby signifying potentially low levels of thrombogenesis.