A Method to Improve Cellular Content for Corporal Tissue Engineering

Abstract

We have previously shown that penile corporal structures engineered using autologous cells are able to achieve erection, penetration, and ejaculation. However, fully functional corpora could not be engineered because of the limited cellular content present within the corporal tissue construct. In this study, we investigated whether a dynamic seeding approach would improve cellularity within the corporal tissue construct and thereby restore normal erectile function. Corporal cells were either statically or dynamically seeded on acellular corporal tissue matrices and maintained in a bioreactor system. After 48 h, the cell-matrix complexes were implanted subcutaneously in athymic mice and analyzed for cell attachment, survival, and distribution using histological and molecular techniques. Native tissues and matrices without cells served as controls. The seeded cells attached and proliferated within the sinusoidal walls of the matrices. After completing the seeding, the DNA and cellular content of the dynamically seeded matrices reached 71% of normal corpora, whereas the statically seeded matrices reached 39% of normal corpora. These findings were confirmed histologically, biochemically, and using scanning electron microscopy. This study demonstrates that dynamic cell attachment, using a bioreactor system, leads to the formation of morphologically and biochemically improved corporal tissue, which may be useful for penile reconstruction.

Bioengineered corporal tissue for structural and functional restoration of the penis

“…Thus, in this study, we engineered entire segments of the pendular neocorpora, using autologous cells and maximized the SMC content. A multistep dynamic/ static seeding procedure was used (14). With this method, we were able to seed 5.9 times as many SMC than our prior experiments.…”

“…A multistep static/dynamic seeding method was used to improve cell attachment and homogeneity on the matrices (14). On the first seeding day, approximately 60 × 10 6 SMC/mL were injected into the decellularized corporal tissue matrix at multiple sites using a 22-gauge needle, and then the construct was placed in culture for 24 h in DMEM supplemented with 10% FBS and 1% penicillin-streptomycin.…”

“…The corpora collagen matrices were prepared from donor rabbit phalluses using an established decellularization process (10). Matrices were seeded with the autologous SMC and EC using a multistep cell seeding protocol (14). The cell-seeded matrices were used to replace the entire pendular penile corpora in 12 male New Zealand White rabbits.…”

Emerging and Novel Therapeutic Approaches in the Treatment of Male Erectile Dysfunction

“…The same group also reported that cultured human corporal smooth muscle and endothelial cells seeded on biodegradable acellular matrix-derived donor rabbit corpora exhibited much better functional and morphologic results compared to unseeded control animals due to the ability to form well-vascularized corporal tissues in vivo [85]. Furthermore, dynamically seeded corporal cells on acellular corporal tissue matrices and maintained in a bioreactor system resulted in improved formation of normal corpora (71% vs. 39% in statically seeded matrices) due to more dynamic cell attachment [86]. In addition to the engineered neo-corpora, cavernous nerve-excised rats, when implanted with acellular nerve grafts, demonstrated adequate ICP at 3 months and the presence of host-cell Adipose-derived stem cell Hypercholesterolemic rat ↑ ICP, nNOS, smooth muscle, and endothelial markers Huang et al [79] Adipose-derived stem cell CNI rat ↑ ICP, nNOS, and SMC preservation cGMP-cyclic guanosine monophosphate; CNI-cavernous nerve injury; eNOS-endothelial nitric oxide synthase; ICP-intracavernosal pressure; nNOS-neuronal nitric oxide synthase; NOS-nitric oxide synthase; SMC-smooth muscle cell infiltration within the nerve sheath [87].…”

Genitourinary System

“…Biodegradable scaffolds have been used as cell delivery systems in many tissue-engineering studies. Recently, a scaffoldless cavernous-tissue-engineering method has been described [84]. Here, rat adipose tissuederived stem cells were isolated and differentiated into SMCs and used with ECs to construct cavernous tissue.…”