CELL - BASED NANOCOMPOSITES AND BIOMOLECULES FOR BONE TISSUE ENGINEERING - Advanced Biomaterials: Fundamentals, Processing, and Applications - page 567

Another noteworthy issue to address is that biological pathways are complex
and the gene expression studies of certain bone markers may not project a holis-
tic overview or analysis of the differentiation of progenitor or stem cells derived
from various sources. As such, the choice of cells to be seeded on the graft ma-
terials based on preliminary gene expression results must always be tested in an
in vivo setting, in order to fully evaluate the reliability of the cell-material con-
struct. Current work on biological pathways is just a tip of the iceberg and still
nebulous, as the portrayal of the evidence changes. Despite many studies that
have shown promising results and have opened avenues for further evaluation,
the intricate molecular interplay between growth factors, cells, proteins need to
be extensively reviewed before synergistic cocktails can be formulated for effec-
tive bone formation.
Stem cell work needs to be investigated more thoroughly for the advance-
ment of regenerative medicine in bone applications. The contributing factors that
led to the confl icting results of the isolation, proliferative, and differentiation
potential of MSCs derived from various sources can be elucidated by the fact
that there are different tissue-harvesting techniques (which may be surgeon-
dependent or donor-site dependent) as well as MSCs isolation methods that are
employed. The amount of tissue harvested is another consideration when dealing
with MCS numbers. Furthermore, patient variability such as age, gender and
medical condition can impinge data consistency across the board 137,152 . Moreover,
the scientifi c community needs to convince the general public of the notion of
viral or gene delivery approaches in order for these options to be utilized clini-
cally. Ideally, corroborative or contradictory evidence must be addressed, or,
when necessary, reconciled to increase public confi dence in these areas.

16.6 CONCLUSION

In conclusion, effi cacious bone regeneration using tissue-engineered constructs
loaded with factors that create a favorable environment in vivo can revolutionize
the clinical management of bone-related diseases and orthopedic applications.
Suitable culture supplements such as dexamethasone, ascorbic acid,

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glycerophosphate, and so on, induced the proliferation and differentiation of
several cell types. From the various studies, the functional property of nano-HA
over conventional bioceramics such as TCP is favorable to cellular response.
Material selection is also vital for the success of the tissue- engineered construct.
One must weigh the pros and cons of both synthetic and natural polymers
and decide which are deemed as the more important material properties needed
to achieve the desired construct. Biomimetic mineralization of nanofi brous
composites, especially those made of collagen and nano-HA, seemed to be
promising because collagen and nano-HA are the main components of native
bone. In addition, mineralization is more evident in nanofi brous scaffolds than
in solid-walled scaffolds. Such nanofi brous scaffolds can be fabricated via an
electrospinning technology. One of the disadvantages of electrospinning is

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